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feature/co
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scraper-uc
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7
.gitignore
vendored
7
.gitignore
vendored
@@ -202,5 +202,10 @@ todo.md
|
||||
git_changes.py
|
||||
git_changes.md
|
||||
pypi_build.sh
|
||||
git_issues.py
|
||||
git_issues.md
|
||||
|
||||
.tests/
|
||||
.tests/
|
||||
.issues/
|
||||
.docs/
|
||||
.issues/
|
||||
3
crawl4ai/scraper/__init__.py
Normal file
3
crawl4ai/scraper/__init__.py
Normal file
@@ -0,0 +1,3 @@
|
||||
from .async_web_scraper import AsyncWebScraper
|
||||
from .bfs_scraper_strategy import BFSScraperStrategy
|
||||
from .filters import URLFilter, FilterChain, URLPatternFilter, ContentTypeFilter
|
||||
123
crawl4ai/scraper/async_web_scraper.py
Normal file
123
crawl4ai/scraper/async_web_scraper.py
Normal file
@@ -0,0 +1,123 @@
|
||||
from typing import Union, AsyncGenerator, Optional
|
||||
from .scraper_strategy import ScraperStrategy
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||||
from .models import ScraperResult, CrawlResult
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||||
from ..async_webcrawler import AsyncWebCrawler
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||||
import logging
|
||||
from dataclasses import dataclass
|
||||
from contextlib import asynccontextmanager
|
||||
|
||||
@dataclass
|
||||
class ScrapingProgress:
|
||||
"""Tracks the progress of a scraping operation."""
|
||||
processed_urls: int = 0
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||||
failed_urls: int = 0
|
||||
current_url: Optional[str] = None
|
||||
|
||||
class AsyncWebScraper:
|
||||
"""
|
||||
A high-level web scraper that combines an async crawler with a scraping strategy.
|
||||
|
||||
Args:
|
||||
crawler (AsyncWebCrawler): The async web crawler implementation
|
||||
strategy (ScraperStrategy): The scraping strategy to use
|
||||
logger (Optional[logging.Logger]): Custom logger for the scraper
|
||||
"""
|
||||
|
||||
def __init__(
|
||||
self,
|
||||
crawler: AsyncWebCrawler,
|
||||
strategy: ScraperStrategy,
|
||||
logger: Optional[logging.Logger] = None
|
||||
):
|
||||
if not isinstance(crawler, AsyncWebCrawler):
|
||||
raise TypeError("crawler must be an instance of AsyncWebCrawler")
|
||||
if not isinstance(strategy, ScraperStrategy):
|
||||
raise TypeError("strategy must be an instance of ScraperStrategy")
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||||
|
||||
self.crawler = crawler
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||||
self.strategy = strategy
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||||
self.logger = logger or logging.getLogger(__name__)
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||||
self._progress = ScrapingProgress()
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||||
|
||||
@property
|
||||
def progress(self) -> ScrapingProgress:
|
||||
"""Get current scraping progress."""
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||||
return self._progress
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||||
|
||||
@asynccontextmanager
|
||||
async def _error_handling_context(self, url: str):
|
||||
"""Context manager for handling errors during scraping."""
|
||||
try:
|
||||
yield
|
||||
except Exception as e:
|
||||
self.logger.error(f"Error scraping {url}: {str(e)}")
|
||||
self._progress.failed_urls += 1
|
||||
raise
|
||||
|
||||
async def ascrape(
|
||||
self,
|
||||
url: str,
|
||||
parallel_processing: bool = True,
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||||
stream: bool = False
|
||||
) -> Union[AsyncGenerator[CrawlResult, None], ScraperResult]:
|
||||
"""
|
||||
Scrape a website starting from the given URL.
|
||||
|
||||
Args:
|
||||
url: Starting URL for scraping
|
||||
parallel_processing: Whether to process URLs in parallel
|
||||
stream: If True, yield results as they come; if False, collect all results
|
||||
|
||||
Returns:
|
||||
Either an async generator yielding CrawlResults or a final ScraperResult
|
||||
"""
|
||||
self._progress = ScrapingProgress() # Reset progress
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||||
|
||||
async with self._error_handling_context(url):
|
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if stream:
|
||||
return self._ascrape_yielding(url, parallel_processing)
|
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return await self._ascrape_collecting(url, parallel_processing)
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||||
|
||||
async def _ascrape_yielding(
|
||||
self,
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||||
url: str,
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||||
parallel_processing: bool
|
||||
) -> AsyncGenerator[CrawlResult, None]:
|
||||
"""Stream scraping results as they become available."""
|
||||
try:
|
||||
result_generator = self.strategy.ascrape(url, self.crawler, parallel_processing)
|
||||
async for res in result_generator:
|
||||
self._progress.processed_urls += 1
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||||
self._progress.current_url = res.url
|
||||
yield res
|
||||
except Exception as e:
|
||||
self.logger.error(f"Error in streaming scrape: {str(e)}")
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||||
raise
|
||||
|
||||
async def _ascrape_collecting(
|
||||
self,
|
||||
url: str,
|
||||
parallel_processing: bool
|
||||
) -> ScraperResult:
|
||||
"""Collect all scraping results before returning."""
|
||||
extracted_data = {}
|
||||
|
||||
try:
|
||||
result_generator = self.strategy.ascrape(url, self.crawler, parallel_processing)
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async for res in result_generator:
|
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self._progress.processed_urls += 1
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||||
self._progress.current_url = res.url
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||||
extracted_data[res.url] = res
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||||
|
||||
return ScraperResult(
|
||||
url=url,
|
||||
crawled_urls=list(extracted_data.keys()),
|
||||
extracted_data=extracted_data,
|
||||
stats={
|
||||
'processed_urls': self._progress.processed_urls,
|
||||
'failed_urls': self._progress.failed_urls
|
||||
}
|
||||
)
|
||||
except Exception as e:
|
||||
self.logger.error(f"Error in collecting scrape: {str(e)}")
|
||||
raise
|
||||
327
crawl4ai/scraper/bfs_scraper_strategy.py
Normal file
327
crawl4ai/scraper/bfs_scraper_strategy.py
Normal file
@@ -0,0 +1,327 @@
|
||||
from abc import ABC, abstractmethod
|
||||
from typing import Union, AsyncGenerator, Optional, Dict, Set
|
||||
from dataclasses import dataclass
|
||||
from datetime import datetime
|
||||
import asyncio
|
||||
import logging
|
||||
from urllib.parse import urljoin, urlparse, urlunparse
|
||||
from urllib.robotparser import RobotFileParser
|
||||
import validators
|
||||
import time
|
||||
from aiolimiter import AsyncLimiter
|
||||
from tenacity import retry, stop_after_attempt, wait_exponential
|
||||
from collections import defaultdict
|
||||
|
||||
from .models import ScraperResult, CrawlResult
|
||||
from .filters import FilterChain
|
||||
from .scorers import URLScorer
|
||||
from ..async_webcrawler import AsyncWebCrawler
|
||||
|
||||
@dataclass
|
||||
class CrawlStats:
|
||||
"""Statistics for the crawling process"""
|
||||
start_time: datetime
|
||||
urls_processed: int = 0
|
||||
urls_failed: int = 0
|
||||
urls_skipped: int = 0
|
||||
total_depth_reached: int = 0
|
||||
current_depth: int = 0
|
||||
robots_blocked: int = 0
|
||||
|
||||
class ScraperStrategy(ABC):
|
||||
"""Base class for scraping strategies"""
|
||||
|
||||
@abstractmethod
|
||||
async def ascrape(
|
||||
self,
|
||||
url: str,
|
||||
crawler: AsyncWebCrawler,
|
||||
parallel_processing: bool = True,
|
||||
stream: bool = False
|
||||
) -> Union[AsyncGenerator[CrawlResult, None], ScraperResult]:
|
||||
"""Abstract method for scraping implementation"""
|
||||
pass
|
||||
|
||||
@abstractmethod
|
||||
async def can_process_url(self, url: str) -> bool:
|
||||
"""Check if URL can be processed based on strategy rules"""
|
||||
pass
|
||||
|
||||
@abstractmethod
|
||||
async def shutdown(self):
|
||||
"""Clean up resources used by the strategy"""
|
||||
pass
|
||||
|
||||
class BFSScraperStrategy(ScraperStrategy):
|
||||
"""Breadth-First Search scraping strategy with politeness controls"""
|
||||
|
||||
def __init__(
|
||||
self,
|
||||
max_depth: int,
|
||||
filter_chain: FilterChain,
|
||||
url_scorer: URLScorer,
|
||||
max_concurrent: int = 5,
|
||||
min_crawl_delay: int = 1,
|
||||
timeout: int = 30,
|
||||
logger: Optional[logging.Logger] = None
|
||||
):
|
||||
self.max_depth = max_depth
|
||||
self.filter_chain = filter_chain
|
||||
self.url_scorer = url_scorer
|
||||
self.max_concurrent = max_concurrent
|
||||
self.min_crawl_delay = min_crawl_delay
|
||||
self.timeout = timeout
|
||||
self.logger = logger or logging.getLogger(__name__)
|
||||
|
||||
# Crawl control
|
||||
self.stats = CrawlStats(start_time=datetime.now())
|
||||
self._cancel_event = asyncio.Event()
|
||||
self.process_external_links = False
|
||||
|
||||
# Rate limiting and politeness
|
||||
self.rate_limiter = AsyncLimiter(1, 1)
|
||||
self.last_crawl_time = defaultdict(float)
|
||||
self.robot_parsers: Dict[str, RobotFileParser] = {}
|
||||
self.domain_queues: Dict[str, asyncio.Queue] = defaultdict(asyncio.Queue)
|
||||
|
||||
async def can_process_url(self, url: str) -> bool:
|
||||
"""Check if URL can be processed based on robots.txt and filters
|
||||
This is our gatekeeper method that determines if a URL should be processed. It:
|
||||
- Validates URL format using the validators library
|
||||
- Checks robots.txt permissions for the domain
|
||||
- Applies custom filters from the filter chain
|
||||
- Updates statistics for blocked URLs
|
||||
- Returns False early if any check fails
|
||||
"""
|
||||
if not validators.url(url):
|
||||
self.logger.warning(f"Invalid URL: {url}")
|
||||
return False
|
||||
|
||||
robot_parser = await self._get_robot_parser(url)
|
||||
if robot_parser and not robot_parser.can_fetch("*", url):
|
||||
self.stats.robots_blocked += 1
|
||||
self.logger.info(f"Blocked by robots.txt: {url}")
|
||||
return False
|
||||
|
||||
return self.filter_chain.apply(url)
|
||||
|
||||
async def _get_robot_parser(self, url: str) -> Optional[RobotFileParser]:
|
||||
"""Get or create robots.txt parser for domain.
|
||||
This is our robots.txt manager that:
|
||||
- Uses domain-level caching of robot parsers
|
||||
- Creates and caches new parsers as needed
|
||||
- Handles failed robots.txt fetches gracefully
|
||||
- Returns None if robots.txt can't be fetched, allowing crawling to proceed
|
||||
"""
|
||||
domain = urlparse(url).netloc
|
||||
if domain not in self.robot_parsers:
|
||||
parser = RobotFileParser()
|
||||
try:
|
||||
robots_url = f"{urlparse(url).scheme}://{domain}/robots.txt"
|
||||
parser.set_url(robots_url)
|
||||
parser.read()
|
||||
self.robot_parsers[domain] = parser
|
||||
except Exception as e:
|
||||
self.logger.warning(f"Error fetching robots.txt for {domain}: {e}")
|
||||
return None
|
||||
return self.robot_parsers[domain]
|
||||
|
||||
@retry(stop=stop_after_attempt(3),
|
||||
wait=wait_exponential(multiplier=1, min=4, max=10))
|
||||
async def _crawl_with_retry(
|
||||
self,
|
||||
crawler: AsyncWebCrawler,
|
||||
url: str
|
||||
) -> CrawlResult:
|
||||
"""Crawl URL with retry logic"""
|
||||
try:
|
||||
async with asyncio.timeout(self.timeout):
|
||||
return await crawler.arun(url)
|
||||
except asyncio.TimeoutError:
|
||||
self.logger.error(f"Timeout crawling {url}")
|
||||
raise
|
||||
|
||||
async def process_url(
|
||||
self,
|
||||
url: str,
|
||||
depth: int,
|
||||
crawler: AsyncWebCrawler,
|
||||
queue: asyncio.PriorityQueue,
|
||||
visited: Set[str],
|
||||
depths: Dict[str, int]
|
||||
) -> Optional[CrawlResult]:
|
||||
"""Process a single URL and extract links.
|
||||
This is our main URL processing workhorse that:
|
||||
- Checks for cancellation
|
||||
- Validates URLs through can_process_url
|
||||
- Implements politeness delays per domain
|
||||
- Applies rate limiting
|
||||
- Handles crawling with retries
|
||||
- Updates various statistics
|
||||
- Processes extracted links
|
||||
- Returns the crawl result or None on failure
|
||||
"""
|
||||
|
||||
if self._cancel_event.is_set():
|
||||
return None
|
||||
|
||||
if not await self.can_process_url(url):
|
||||
self.stats.urls_skipped += 1
|
||||
return None
|
||||
|
||||
# Politeness delay
|
||||
domain = urlparse(url).netloc
|
||||
time_since_last = time.time() - self.last_crawl_time[domain]
|
||||
if time_since_last < self.min_crawl_delay:
|
||||
await asyncio.sleep(self.min_crawl_delay - time_since_last)
|
||||
self.last_crawl_time[domain] = time.time()
|
||||
|
||||
# Crawl with rate limiting
|
||||
try:
|
||||
async with self.rate_limiter:
|
||||
result = await self._crawl_with_retry(crawler, url)
|
||||
self.stats.urls_processed += 1
|
||||
except Exception as e:
|
||||
self.logger.error(f"Error crawling {url}: {e}")
|
||||
self.stats.urls_failed += 1
|
||||
return None
|
||||
|
||||
# Process links
|
||||
await self._process_links(result, url, depth, queue, visited, depths)
|
||||
|
||||
return result
|
||||
|
||||
async def _process_links(
|
||||
self,
|
||||
result: CrawlResult,
|
||||
source_url: str,
|
||||
depth: int,
|
||||
queue: asyncio.PriorityQueue,
|
||||
visited: Set[str],
|
||||
depths: Dict[str, int]
|
||||
):
|
||||
"""Process extracted links from crawl result.
|
||||
This is our link processor that:
|
||||
Handles both internal and external links
|
||||
Normalizes URLs (removes fragments)
|
||||
Checks depth limits
|
||||
Scores URLs for priority
|
||||
Updates depth tracking
|
||||
Adds valid URLs to the queue
|
||||
Updates maximum depth statistics
|
||||
"""
|
||||
links_ro_process = result.links["internal"]
|
||||
if self.process_external_links:
|
||||
links_ro_process += result.links["external"]
|
||||
for link_type in links_ro_process:
|
||||
for link in result.links[link_type]:
|
||||
url = link['href']
|
||||
# url = urljoin(source_url, link['href'])
|
||||
# url = urlunparse(urlparse(url)._replace(fragment=""))
|
||||
|
||||
if url not in visited and await self.can_process_url(url):
|
||||
new_depth = depths[source_url] + 1
|
||||
if new_depth <= self.max_depth:
|
||||
score = self.url_scorer.score(url)
|
||||
await queue.put((score, new_depth, url))
|
||||
depths[url] = new_depth
|
||||
self.stats.total_depth_reached = max(
|
||||
self.stats.total_depth_reached,
|
||||
new_depth
|
||||
)
|
||||
|
||||
async def ascrape(
|
||||
self,
|
||||
start_url: str,
|
||||
crawler: AsyncWebCrawler,
|
||||
parallel_processing: bool = True
|
||||
) -> AsyncGenerator[CrawlResult, None]:
|
||||
"""Implement BFS crawling strategy"""
|
||||
|
||||
# Initialize crawl state
|
||||
"""
|
||||
queue: A priority queue where items are tuples of (score, depth, url)
|
||||
Score: Determines crawling priority (lower = higher priority)
|
||||
Depth: Current distance from start_url
|
||||
URL: The actual URL to crawl
|
||||
visited: Keeps track of URLs we've already seen to avoid cycles
|
||||
depths: Maps URLs to their depths from the start URL
|
||||
pending_tasks: Tracks currently running crawl tasks
|
||||
"""
|
||||
queue = asyncio.PriorityQueue()
|
||||
await queue.put((0, 0, start_url))
|
||||
visited: Set[str] = set()
|
||||
depths = {start_url: 0}
|
||||
pending_tasks = set()
|
||||
|
||||
try:
|
||||
while (not queue.empty() or pending_tasks) and not self._cancel_event.is_set():
|
||||
"""
|
||||
This sets up our main control loop which:
|
||||
- Continues while there are URLs to process (not queue.empty())
|
||||
- Or while there are tasks still running (pending_tasks)
|
||||
- Can be interrupted via cancellation (not self._cancel_event.is_set())
|
||||
"""
|
||||
# Start new tasks up to max_concurrent
|
||||
while not queue.empty() and len(pending_tasks) < self.max_concurrent:
|
||||
"""
|
||||
This section manages task creation:
|
||||
Checks if we can start more tasks (under max_concurrent limit)
|
||||
Gets the next URL from the priority queue
|
||||
Marks URLs as visited immediately to prevent duplicates
|
||||
Updates current depth in stats
|
||||
Either:
|
||||
Creates a new async task (parallel mode)
|
||||
Processes URL directly (sequential mode)
|
||||
"""
|
||||
_, depth, url = await queue.get()
|
||||
if url not in visited:
|
||||
visited.add(url)
|
||||
self.stats.current_depth = depth
|
||||
|
||||
if parallel_processing:
|
||||
task = asyncio.create_task(
|
||||
self.process_url(url, depth, crawler, queue, visited, depths)
|
||||
)
|
||||
pending_tasks.add(task)
|
||||
else:
|
||||
result = await self.process_url(
|
||||
url, depth, crawler, queue, visited, depths
|
||||
)
|
||||
if result:
|
||||
yield result
|
||||
|
||||
# Process completed tasks
|
||||
"""
|
||||
This section manages completed tasks:
|
||||
Waits for any task to complete using asyncio.wait
|
||||
Uses FIRST_COMPLETED to handle results as soon as they're ready
|
||||
Yields successful results to the caller
|
||||
Updates pending_tasks to remove completed ones
|
||||
"""
|
||||
if pending_tasks:
|
||||
done, pending_tasks = await asyncio.wait(
|
||||
pending_tasks,
|
||||
return_when=asyncio.FIRST_COMPLETED
|
||||
)
|
||||
for task in done:
|
||||
result = await task
|
||||
if result:
|
||||
yield result
|
||||
|
||||
except Exception as e:
|
||||
self.logger.error(f"Error in crawl process: {e}")
|
||||
raise
|
||||
|
||||
finally:
|
||||
# Clean up any remaining tasks
|
||||
for task in pending_tasks:
|
||||
task.cancel()
|
||||
self.stats.end_time = datetime.now()
|
||||
|
||||
async def shutdown(self):
|
||||
"""Clean up resources and stop crawling"""
|
||||
self._cancel_event.set()
|
||||
# Clear caches and close connections
|
||||
self.robot_parsers.clear()
|
||||
self.domain_queues.clear()
|
||||
205
crawl4ai/scraper/filters.py
Normal file
205
crawl4ai/scraper/filters.py
Normal file
@@ -0,0 +1,205 @@
|
||||
# from .url_filter import URLFilter, FilterChain
|
||||
# from .content_type_filter import ContentTypeFilter
|
||||
# from .url_pattern_filter import URLPatternFilter
|
||||
|
||||
from abc import ABC, abstractmethod
|
||||
from typing import List, Pattern, Set, Union
|
||||
import re
|
||||
from urllib.parse import urlparse
|
||||
import mimetypes
|
||||
import logging
|
||||
from dataclasses import dataclass
|
||||
import fnmatch
|
||||
|
||||
@dataclass
|
||||
class FilterStats:
|
||||
"""Statistics for filter applications"""
|
||||
total_urls: int = 0
|
||||
rejected_urls: int = 0
|
||||
passed_urls: int = 0
|
||||
|
||||
class URLFilter(ABC):
|
||||
"""Base class for URL filters"""
|
||||
|
||||
def __init__(self, name: str = None):
|
||||
self.name = name or self.__class__.__name__
|
||||
self.stats = FilterStats()
|
||||
self.logger = logging.getLogger(f"urlfilter.{self.name}")
|
||||
|
||||
@abstractmethod
|
||||
def apply(self, url: str) -> bool:
|
||||
"""Apply the filter to a URL"""
|
||||
pass
|
||||
|
||||
def _update_stats(self, passed: bool):
|
||||
"""Update filter statistics"""
|
||||
self.stats.total_urls += 1
|
||||
if passed:
|
||||
self.stats.passed_urls += 1
|
||||
else:
|
||||
self.stats.rejected_urls += 1
|
||||
|
||||
class FilterChain:
|
||||
"""Chain of URL filters."""
|
||||
|
||||
def __init__(self, filters: List[URLFilter] = None):
|
||||
self.filters = filters or []
|
||||
self.stats = FilterStats()
|
||||
self.logger = logging.getLogger("urlfilter.chain")
|
||||
|
||||
def add_filter(self, filter_: URLFilter) -> 'FilterChain':
|
||||
"""Add a filter to the chain"""
|
||||
self.filters.append(filter_)
|
||||
return self # Enable method chaining
|
||||
|
||||
def apply(self, url: str) -> bool:
|
||||
"""Apply all filters in the chain"""
|
||||
self.stats.total_urls += 1
|
||||
|
||||
for filter_ in self.filters:
|
||||
if not filter_.apply(url):
|
||||
self.stats.rejected_urls += 1
|
||||
self.logger.debug(f"URL {url} rejected by {filter_.name}")
|
||||
return False
|
||||
|
||||
self.stats.passed_urls += 1
|
||||
return True
|
||||
|
||||
class URLPatternFilter(URLFilter):
|
||||
"""Filter URLs based on glob patterns or regex.
|
||||
|
||||
pattern_filter = URLPatternFilter([
|
||||
"*.example.com/*", # Glob pattern
|
||||
"*/article/*", # Path pattern
|
||||
re.compile(r"blog-\d+") # Regex pattern
|
||||
])
|
||||
|
||||
- Supports glob patterns and regex
|
||||
- Multiple patterns per filter
|
||||
- Pattern pre-compilation for performance
|
||||
"""
|
||||
|
||||
def __init__(self, patterns: Union[str, Pattern, List[Union[str, Pattern]]],
|
||||
use_glob: bool = True):
|
||||
super().__init__()
|
||||
self.patterns = [patterns] if isinstance(patterns, (str, Pattern)) else patterns
|
||||
self.use_glob = use_glob
|
||||
self._compiled_patterns = []
|
||||
|
||||
for pattern in self.patterns:
|
||||
if isinstance(pattern, str) and use_glob:
|
||||
self._compiled_patterns.append(self._glob_to_regex(pattern))
|
||||
else:
|
||||
self._compiled_patterns.append(re.compile(pattern) if isinstance(pattern, str) else pattern)
|
||||
|
||||
def _glob_to_regex(self, pattern: str) -> Pattern:
|
||||
"""Convert glob pattern to regex"""
|
||||
return re.compile(fnmatch.translate(pattern))
|
||||
|
||||
def apply(self, url: str) -> bool:
|
||||
"""Check if URL matches any of the patterns"""
|
||||
matches = any(pattern.search(url) for pattern in self._compiled_patterns)
|
||||
self._update_stats(matches)
|
||||
return matches
|
||||
|
||||
class ContentTypeFilter(URLFilter):
|
||||
"""Filter URLs based on expected content type.
|
||||
|
||||
content_filter = ContentTypeFilter([
|
||||
"text/html",
|
||||
"application/pdf"
|
||||
], check_extension=True)
|
||||
|
||||
- Filter by MIME types
|
||||
- Extension checking
|
||||
- Support for multiple content types
|
||||
"""
|
||||
|
||||
def __init__(self, allowed_types: Union[str, List[str]],
|
||||
check_extension: bool = True):
|
||||
super().__init__()
|
||||
self.allowed_types = [allowed_types] if isinstance(allowed_types, str) else allowed_types
|
||||
self.check_extension = check_extension
|
||||
self._normalize_types()
|
||||
|
||||
def _normalize_types(self):
|
||||
"""Normalize content type strings"""
|
||||
self.allowed_types = [t.lower() for t in self.allowed_types]
|
||||
|
||||
def _check_extension(self, url: str) -> bool:
|
||||
"""Check URL's file extension"""
|
||||
ext = urlparse(url).path.split('.')[-1].lower() if '.' in urlparse(url).path else ''
|
||||
if not ext:
|
||||
return True # No extension, might be dynamic content
|
||||
|
||||
guessed_type = mimetypes.guess_type(url)[0]
|
||||
return any(allowed in (guessed_type or '').lower() for allowed in self.allowed_types)
|
||||
|
||||
def apply(self, url: str) -> bool:
|
||||
"""Check if URL's content type is allowed"""
|
||||
result = True
|
||||
if self.check_extension:
|
||||
result = self._check_extension(url)
|
||||
self._update_stats(result)
|
||||
return result
|
||||
|
||||
class DomainFilter(URLFilter):
|
||||
"""Filter URLs based on allowed/blocked domains.
|
||||
|
||||
domain_filter = DomainFilter(
|
||||
allowed_domains=["example.com", "blog.example.com"],
|
||||
blocked_domains=["ads.example.com"]
|
||||
)
|
||||
|
||||
- Allow/block specific domains
|
||||
- Subdomain support
|
||||
- Efficient domain matching
|
||||
"""
|
||||
|
||||
def __init__(self, allowed_domains: Union[str, List[str]] = None,
|
||||
blocked_domains: Union[str, List[str]] = None):
|
||||
super().__init__()
|
||||
self.allowed_domains = set(self._normalize_domains(allowed_domains)) if allowed_domains else None
|
||||
self.blocked_domains = set(self._normalize_domains(blocked_domains)) if blocked_domains else set()
|
||||
|
||||
def _normalize_domains(self, domains: Union[str, List[str]]) -> List[str]:
|
||||
"""Normalize domain strings"""
|
||||
if isinstance(domains, str):
|
||||
domains = [domains]
|
||||
return [d.lower().strip() for d in domains]
|
||||
|
||||
def _extract_domain(self, url: str) -> str:
|
||||
"""Extract domain from URL"""
|
||||
return urlparse(url).netloc.lower()
|
||||
|
||||
def apply(self, url: str) -> bool:
|
||||
"""Check if URL's domain is allowed"""
|
||||
domain = self._extract_domain(url)
|
||||
|
||||
if domain in self.blocked_domains:
|
||||
self._update_stats(False)
|
||||
return False
|
||||
|
||||
if self.allowed_domains is not None and domain not in self.allowed_domains:
|
||||
self._update_stats(False)
|
||||
return False
|
||||
|
||||
self._update_stats(True)
|
||||
return True
|
||||
|
||||
# Example usage:
|
||||
def create_common_filter_chain() -> FilterChain:
|
||||
"""Create a commonly used filter chain"""
|
||||
return FilterChain([
|
||||
URLPatternFilter([
|
||||
"*.html", "*.htm", # HTML files
|
||||
"*/article/*", "*/blog/*" # Common content paths
|
||||
]),
|
||||
ContentTypeFilter([
|
||||
"text/html",
|
||||
"application/xhtml+xml"
|
||||
]),
|
||||
DomainFilter(
|
||||
blocked_domains=["ads.*", "analytics.*"]
|
||||
)
|
||||
])
|
||||
8
crawl4ai/scraper/models.py
Normal file
8
crawl4ai/scraper/models.py
Normal file
@@ -0,0 +1,8 @@
|
||||
from pydantic import BaseModel
|
||||
from typing import List, Dict
|
||||
from ..models import CrawlResult
|
||||
|
||||
class ScraperResult(BaseModel):
|
||||
url: str
|
||||
crawled_urls: List[str]
|
||||
extracted_data: Dict[str,CrawlResult]
|
||||
268
crawl4ai/scraper/scorers.py
Normal file
268
crawl4ai/scraper/scorers.py
Normal file
@@ -0,0 +1,268 @@
|
||||
# from .url_scorer import URLScorer
|
||||
# from .keyword_relevance_scorer import KeywordRelevanceScorer
|
||||
|
||||
from abc import ABC, abstractmethod
|
||||
from typing import List, Dict, Optional, Union
|
||||
from dataclasses import dataclass
|
||||
from urllib.parse import urlparse, unquote
|
||||
import re
|
||||
from collections import defaultdict
|
||||
import math
|
||||
import logging
|
||||
|
||||
@dataclass
|
||||
class ScoringStats:
|
||||
"""Statistics for URL scoring"""
|
||||
urls_scored: int = 0
|
||||
total_score: float = 0.0
|
||||
min_score: float = float('inf')
|
||||
max_score: float = float('-inf')
|
||||
|
||||
def update(self, score: float):
|
||||
"""Update scoring statistics"""
|
||||
self.urls_scored += 1
|
||||
self.total_score += score
|
||||
self.min_score = min(self.min_score, score)
|
||||
self.max_score = max(self.max_score, score)
|
||||
|
||||
@property
|
||||
def average_score(self) -> float:
|
||||
"""Calculate average score"""
|
||||
return self.total_score / self.urls_scored if self.urls_scored > 0 else 0.0
|
||||
|
||||
class URLScorer(ABC):
|
||||
"""Base class for URL scoring strategies"""
|
||||
|
||||
def __init__(self, weight: float = 1.0, name: str = None):
|
||||
self.weight = weight
|
||||
self.name = name or self.__class__.__name__
|
||||
self.stats = ScoringStats()
|
||||
self.logger = logging.getLogger(f"urlscorer.{self.name}")
|
||||
|
||||
@abstractmethod
|
||||
def _calculate_score(self, url: str) -> float:
|
||||
"""Calculate the raw score for a URL"""
|
||||
pass
|
||||
|
||||
def score(self, url: str) -> float:
|
||||
"""Calculate the weighted score for a URL"""
|
||||
raw_score = self._calculate_score(url)
|
||||
weighted_score = raw_score * self.weight
|
||||
self.stats.update(weighted_score)
|
||||
return weighted_score
|
||||
|
||||
class CompositeScorer(URLScorer):
|
||||
"""Combines multiple scorers with weights"""
|
||||
|
||||
def __init__(self, scorers: List[URLScorer], normalize: bool = True):
|
||||
super().__init__(name="CompositeScorer")
|
||||
self.scorers = scorers
|
||||
self.normalize = normalize
|
||||
|
||||
def _calculate_score(self, url: str) -> float:
|
||||
scores = [scorer.score(url) for scorer in self.scorers]
|
||||
total_score = sum(scores)
|
||||
|
||||
if self.normalize and scores:
|
||||
total_score /= len(scores)
|
||||
|
||||
return total_score
|
||||
|
||||
class KeywordRelevanceScorer(URLScorer):
|
||||
"""Score URLs based on keyword relevance.
|
||||
|
||||
keyword_scorer = KeywordRelevanceScorer(
|
||||
keywords=["python", "programming"],
|
||||
weight=1.0,
|
||||
case_sensitive=False
|
||||
)
|
||||
|
||||
- Score based on keyword matches
|
||||
- Case sensitivity options
|
||||
- Weighted scoring
|
||||
"""
|
||||
|
||||
def __init__(self, keywords: List[str], weight: float = 1.0,
|
||||
case_sensitive: bool = False):
|
||||
super().__init__(weight=weight)
|
||||
self.keywords = keywords
|
||||
self.case_sensitive = case_sensitive
|
||||
self._compile_keywords()
|
||||
|
||||
def _compile_keywords(self):
|
||||
"""Prepare keywords for matching"""
|
||||
flags = 0 if self.case_sensitive else re.IGNORECASE
|
||||
self.patterns = [re.compile(re.escape(k), flags) for k in self.keywords]
|
||||
|
||||
def _calculate_score(self, url: str) -> float:
|
||||
"""Calculate score based on keyword matches"""
|
||||
decoded_url = unquote(url)
|
||||
total_matches = sum(
|
||||
1 for pattern in self.patterns
|
||||
if pattern.search(decoded_url)
|
||||
)
|
||||
# Normalize score between 0 and 1
|
||||
return total_matches / len(self.patterns) if self.patterns else 0.0
|
||||
|
||||
class PathDepthScorer(URLScorer):
|
||||
"""Score URLs based on their path depth.
|
||||
|
||||
path_scorer = PathDepthScorer(
|
||||
optimal_depth=3, # Preferred URL depth
|
||||
weight=0.7
|
||||
)
|
||||
|
||||
- Score based on URL path depth
|
||||
- Configurable optimal depth
|
||||
- Diminishing returns for deeper paths
|
||||
"""
|
||||
|
||||
def __init__(self, optimal_depth: int = 3, weight: float = 1.0):
|
||||
super().__init__(weight=weight)
|
||||
self.optimal_depth = optimal_depth
|
||||
|
||||
def _calculate_score(self, url: str) -> float:
|
||||
"""Calculate score based on path depth"""
|
||||
path = urlparse(url).path
|
||||
depth = len([x for x in path.split('/') if x])
|
||||
|
||||
# Score decreases as we move away from optimal depth
|
||||
distance_from_optimal = abs(depth - self.optimal_depth)
|
||||
return 1.0 / (1.0 + distance_from_optimal)
|
||||
|
||||
class ContentTypeScorer(URLScorer):
|
||||
"""Score URLs based on content type preferences.
|
||||
|
||||
content_scorer = ContentTypeScorer({
|
||||
r'\.html$': 1.0,
|
||||
r'\.pdf$': 0.8,
|
||||
r'\.xml$': 0.6
|
||||
})
|
||||
|
||||
- Score based on file types
|
||||
- Configurable type weights
|
||||
- Pattern matching support
|
||||
"""
|
||||
|
||||
def __init__(self, type_weights: Dict[str, float], weight: float = 1.0):
|
||||
super().__init__(weight=weight)
|
||||
self.type_weights = type_weights
|
||||
self._compile_patterns()
|
||||
|
||||
def _compile_patterns(self):
|
||||
"""Prepare content type patterns"""
|
||||
self.patterns = {
|
||||
re.compile(pattern): weight
|
||||
for pattern, weight in self.type_weights.items()
|
||||
}
|
||||
|
||||
def _calculate_score(self, url: str) -> float:
|
||||
"""Calculate score based on content type matching"""
|
||||
for pattern, weight in self.patterns.items():
|
||||
if pattern.search(url):
|
||||
return weight
|
||||
return 0.0
|
||||
|
||||
class FreshnessScorer(URLScorer):
|
||||
"""Score URLs based on freshness indicators.
|
||||
|
||||
freshness_scorer = FreshnessScorer(weight=0.9)
|
||||
|
||||
Score based on date indicators in URLs
|
||||
Multiple date format support
|
||||
Recency weighting"""
|
||||
|
||||
def __init__(self, weight: float = 1.0):
|
||||
super().__init__(weight=weight)
|
||||
self.date_patterns = [
|
||||
r'/(\d{4})/(\d{2})/(\d{2})/', # yyyy/mm/dd
|
||||
r'(\d{4})[-_](\d{2})[-_](\d{2})', # yyyy-mm-dd
|
||||
r'/(\d{4})/', # year only
|
||||
]
|
||||
self._compile_patterns()
|
||||
|
||||
def _compile_patterns(self):
|
||||
"""Prepare date patterns"""
|
||||
self.compiled_patterns = [re.compile(p) for p in self.date_patterns]
|
||||
|
||||
def _calculate_score(self, url: str) -> float:
|
||||
"""Calculate score based on date indicators"""
|
||||
for pattern in self.compiled_patterns:
|
||||
if match := pattern.search(url):
|
||||
year = int(match.group(1))
|
||||
# Score higher for more recent years
|
||||
return 1.0 - (2024 - year) * 0.1
|
||||
return 0.5 # Default score for URLs without dates
|
||||
|
||||
class DomainAuthorityScorer(URLScorer):
|
||||
"""Score URLs based on domain authority.
|
||||
|
||||
authority_scorer = DomainAuthorityScorer({
|
||||
"python.org": 1.0,
|
||||
"github.com": 0.9,
|
||||
"medium.com": 0.7
|
||||
})
|
||||
|
||||
Score based on domain importance
|
||||
Configurable domain weights
|
||||
Default weight for unknown domains"""
|
||||
|
||||
def __init__(self, domain_weights: Dict[str, float],
|
||||
default_weight: float = 0.5, weight: float = 1.0):
|
||||
super().__init__(weight=weight)
|
||||
self.domain_weights = domain_weights
|
||||
self.default_weight = default_weight
|
||||
|
||||
def _calculate_score(self, url: str) -> float:
|
||||
"""Calculate score based on domain authority"""
|
||||
domain = urlparse(url).netloc.lower()
|
||||
return self.domain_weights.get(domain, self.default_weight)
|
||||
|
||||
def create_balanced_scorer() -> CompositeScorer:
|
||||
"""Create a balanced composite scorer"""
|
||||
return CompositeScorer([
|
||||
KeywordRelevanceScorer(
|
||||
keywords=["article", "blog", "news", "research"],
|
||||
weight=1.0
|
||||
),
|
||||
PathDepthScorer(
|
||||
optimal_depth=3,
|
||||
weight=0.7
|
||||
),
|
||||
ContentTypeScorer(
|
||||
type_weights={
|
||||
r'\.html?$': 1.0,
|
||||
r'\.pdf$': 0.8,
|
||||
r'\.xml$': 0.6
|
||||
},
|
||||
weight=0.8
|
||||
),
|
||||
FreshnessScorer(
|
||||
weight=0.9
|
||||
)
|
||||
])
|
||||
|
||||
# Example Usage:
|
||||
"""
|
||||
# Create a composite scorer
|
||||
scorer = CompositeScorer([
|
||||
KeywordRelevanceScorer(["python", "programming"], weight=1.0),
|
||||
PathDepthScorer(optimal_depth=2, weight=0.7),
|
||||
FreshnessScorer(weight=0.8),
|
||||
DomainAuthorityScorer(
|
||||
domain_weights={
|
||||
"python.org": 1.0,
|
||||
"github.com": 0.9,
|
||||
"medium.com": 0.7
|
||||
},
|
||||
weight=0.9
|
||||
)
|
||||
])
|
||||
|
||||
# Score a URL
|
||||
score = scorer.score("https://python.org/article/2024/01/new-features")
|
||||
|
||||
# Access statistics
|
||||
print(f"Average score: {scorer.stats.average_score}")
|
||||
print(f"URLs scored: {scorer.stats.urls_scored}")
|
||||
"""
|
||||
26
crawl4ai/scraper/scraper_strategy.py
Normal file
26
crawl4ai/scraper/scraper_strategy.py
Normal file
@@ -0,0 +1,26 @@
|
||||
from abc import ABC, abstractmethod
|
||||
from .models import ScraperResult, CrawlResult
|
||||
from ..models import CrawlResult
|
||||
from ..async_webcrawler import AsyncWebCrawler
|
||||
from typing import Union, AsyncGenerator
|
||||
|
||||
class ScraperStrategy(ABC):
|
||||
@abstractmethod
|
||||
async def ascrape(self, url: str, crawler: AsyncWebCrawler, parallel_processing: bool = True, stream: bool = False) -> Union[AsyncGenerator[CrawlResult, None], ScraperResult]:
|
||||
"""Scrape the given URL using the specified crawler.
|
||||
|
||||
Args:
|
||||
url (str): The starting URL for the scrape.
|
||||
crawler (AsyncWebCrawler): The web crawler instance.
|
||||
parallel_processing (bool): Whether to use parallel processing. Defaults to True.
|
||||
stream (bool): If True, yields individual crawl results as they are ready;
|
||||
if False, accumulates results and returns a final ScraperResult.
|
||||
|
||||
Yields:
|
||||
CrawlResult: Individual crawl results if stream is True.
|
||||
|
||||
Returns:
|
||||
ScraperResult: A summary of the scrape results containing the final extracted data
|
||||
and the list of crawled URLs if stream is False.
|
||||
"""
|
||||
pass
|
||||
166
docs/scrapper/async_web_scraper.md
Normal file
166
docs/scrapper/async_web_scraper.md
Normal file
@@ -0,0 +1,166 @@
|
||||
# AsyncWebScraper: Smart Web Crawling Made Easy
|
||||
|
||||
AsyncWebScraper is a powerful and flexible web scraping tool that makes it easy to collect data from websites efficiently. Whether you need to scrape a few pages or an entire website, AsyncWebScraper handles the complexity of web crawling while giving you fine-grained control over the process.
|
||||
|
||||
## How It Works
|
||||
|
||||
```mermaid
|
||||
flowchart TB
|
||||
Start([Start]) --> Init[Initialize AsyncWebScraper\nwith Crawler and Strategy]
|
||||
Init --> InputURL[Receive URL to scrape]
|
||||
InputURL --> Decision{Stream or\nCollect?}
|
||||
|
||||
%% Streaming Path
|
||||
Decision -->|Stream| StreamInit[Initialize Streaming Mode]
|
||||
StreamInit --> StreamStrategy[Call Strategy.ascrape]
|
||||
StreamStrategy --> AsyncGen[Create Async Generator]
|
||||
AsyncGen --> ProcessURL[Process Next URL]
|
||||
ProcessURL --> FetchContent[Fetch Page Content]
|
||||
FetchContent --> Extract[Extract Data]
|
||||
Extract --> YieldResult[Yield CrawlResult]
|
||||
YieldResult --> CheckMore{More URLs?}
|
||||
CheckMore -->|Yes| ProcessURL
|
||||
CheckMore -->|No| StreamEnd([End Stream])
|
||||
|
||||
%% Collecting Path
|
||||
Decision -->|Collect| CollectInit[Initialize Collection Mode]
|
||||
CollectInit --> CollectStrategy[Call Strategy.ascrape]
|
||||
CollectStrategy --> CollectGen[Create Async Generator]
|
||||
CollectGen --> ProcessURLColl[Process Next URL]
|
||||
ProcessURLColl --> FetchContentColl[Fetch Page Content]
|
||||
FetchContentColl --> ExtractColl[Extract Data]
|
||||
ExtractColl --> StoreColl[Store in Dictionary]
|
||||
StoreColl --> CheckMoreColl{More URLs?}
|
||||
CheckMoreColl -->|Yes| ProcessURLColl
|
||||
CheckMoreColl -->|No| CreateResult[Create ScraperResult]
|
||||
CreateResult --> ReturnResult([Return Result])
|
||||
|
||||
%% Parallel Processing
|
||||
subgraph Parallel
|
||||
ProcessURL
|
||||
FetchContent
|
||||
Extract
|
||||
ProcessURLColl
|
||||
FetchContentColl
|
||||
ExtractColl
|
||||
end
|
||||
|
||||
%% Error Handling
|
||||
FetchContent --> ErrorCheck{Error?}
|
||||
ErrorCheck -->|Yes| LogError[Log Error]
|
||||
LogError --> UpdateStats[Update Error Stats]
|
||||
UpdateStats --> CheckMore
|
||||
ErrorCheck -->|No| Extract
|
||||
|
||||
FetchContentColl --> ErrorCheckColl{Error?}
|
||||
ErrorCheckColl -->|Yes| LogErrorColl[Log Error]
|
||||
LogErrorColl --> UpdateStatsColl[Update Error Stats]
|
||||
UpdateStatsColl --> CheckMoreColl
|
||||
ErrorCheckColl -->|No| ExtractColl
|
||||
|
||||
%% Style definitions
|
||||
classDef process fill:#90caf9,stroke:#000,stroke-width:2px;
|
||||
classDef decision fill:#fff59d,stroke:#000,stroke-width:2px;
|
||||
classDef error fill:#ef9a9a,stroke:#000,stroke-width:2px;
|
||||
classDef start fill:#a5d6a7,stroke:#000,stroke-width:2px;
|
||||
|
||||
class Start,StreamEnd,ReturnResult start;
|
||||
class Decision,CheckMore,CheckMoreColl,ErrorCheck,ErrorCheckColl decision;
|
||||
class LogError,LogErrorColl,UpdateStats,UpdateStatsColl error;
|
||||
class ProcessURL,FetchContent,Extract,ProcessURLColl,FetchContentColl,ExtractColl process;
|
||||
```
|
||||
|
||||
AsyncWebScraper uses an intelligent crawling system that can navigate through websites following your specified strategy. It supports two main modes of operation:
|
||||
|
||||
### 1. Streaming Mode
|
||||
```python
|
||||
async for result in scraper.ascrape(url, stream=True):
|
||||
print(f"Found data on {result.url}")
|
||||
process_data(result.data)
|
||||
```
|
||||
- Perfect for processing large websites
|
||||
- Memory efficient - handles one page at a time
|
||||
- Ideal for real-time data processing
|
||||
- Great for monitoring or continuous scraping tasks
|
||||
|
||||
### 2. Collection Mode
|
||||
```python
|
||||
result = await scraper.ascrape(url)
|
||||
print(f"Scraped {len(result.crawled_urls)} pages")
|
||||
process_all_data(result.extracted_data)
|
||||
```
|
||||
- Collects all data before returning
|
||||
- Best for when you need the complete dataset
|
||||
- Easier to work with for batch processing
|
||||
- Includes comprehensive statistics
|
||||
|
||||
## Key Features
|
||||
|
||||
- **Smart Crawling**: Automatically follows relevant links while avoiding duplicates
|
||||
- **Parallel Processing**: Scrapes multiple pages simultaneously for better performance
|
||||
- **Memory Efficient**: Choose between streaming and collecting based on your needs
|
||||
- **Error Resilient**: Continues working even if some pages fail to load
|
||||
- **Progress Tracking**: Monitor the scraping progress in real-time
|
||||
- **Customizable**: Configure crawling strategy, filters, and scoring to match your needs
|
||||
|
||||
## Quick Start
|
||||
|
||||
```python
|
||||
from crawl4ai.scraper import AsyncWebScraper, BFSStrategy
|
||||
from crawl4ai.async_webcrawler import AsyncWebCrawler
|
||||
|
||||
# Initialize the scraper
|
||||
crawler = AsyncWebCrawler()
|
||||
strategy = BFSStrategy(
|
||||
max_depth=2, # How deep to crawl
|
||||
url_pattern="*.example.com/*" # What URLs to follow
|
||||
)
|
||||
scraper = AsyncWebScraper(crawler, strategy)
|
||||
|
||||
# Start scraping
|
||||
async def main():
|
||||
# Collect all results
|
||||
result = await scraper.ascrape("https://example.com")
|
||||
print(f"Found {len(result.extracted_data)} pages")
|
||||
|
||||
# Or stream results
|
||||
async for page in scraper.ascrape("https://example.com", stream=True):
|
||||
print(f"Processing {page.url}")
|
||||
|
||||
```
|
||||
|
||||
## Best Practices
|
||||
|
||||
1. **Choose the Right Mode**
|
||||
- Use streaming for large websites or real-time processing
|
||||
- Use collecting for smaller sites or when you need the complete dataset
|
||||
|
||||
2. **Configure Depth**
|
||||
- Start with a small depth (2-3) and increase if needed
|
||||
- Higher depths mean exponentially more pages to crawl
|
||||
|
||||
3. **Set Appropriate Filters**
|
||||
- Use URL patterns to stay within relevant sections
|
||||
- Set content type filters to only process useful pages
|
||||
|
||||
4. **Handle Resources Responsibly**
|
||||
- Enable parallel processing for faster results
|
||||
- Consider the target website's capacity
|
||||
- Implement appropriate delays between requests
|
||||
|
||||
## Common Use Cases
|
||||
|
||||
- **Content Aggregation**: Collect articles, blog posts, or news from multiple pages
|
||||
- **Data Extraction**: Gather product information, prices, or specifications
|
||||
- **Site Mapping**: Create a complete map of a website's structure
|
||||
- **Content Monitoring**: Track changes or updates across multiple pages
|
||||
- **Data Mining**: Extract and analyze patterns across web pages
|
||||
|
||||
## Advanced Features
|
||||
|
||||
- Custom scoring algorithms for prioritizing important pages
|
||||
- URL filters for focusing on specific site sections
|
||||
- Content type filtering for processing only relevant pages
|
||||
- Progress tracking for monitoring long-running scrapes
|
||||
|
||||
Need more help? Check out our [examples repository](https://github.com/example/crawl4ai/examples) or join our [community Discord](https://discord.gg/example).
|
||||
244
docs/scrapper/bfs_scraper_strategy.md
Normal file
244
docs/scrapper/bfs_scraper_strategy.md
Normal file
@@ -0,0 +1,244 @@
|
||||
# BFS Scraper Strategy: Smart Web Traversal
|
||||
|
||||
The BFS (Breadth-First Search) Scraper Strategy provides an intelligent way to traverse websites systematically. It crawls websites level by level, ensuring thorough coverage while respecting web crawling etiquette.
|
||||
|
||||
```mermaid
|
||||
flowchart TB
|
||||
Start([Start]) --> Init[Initialize BFS Strategy]
|
||||
Init --> InitStats[Initialize CrawlStats]
|
||||
InitStats --> InitQueue[Initialize Priority Queue]
|
||||
InitQueue --> AddStart[Add Start URL to Queue]
|
||||
|
||||
AddStart --> CheckState{Queue Empty or\nTasks Pending?}
|
||||
CheckState -->|No| Cleanup[Cleanup & Stats]
|
||||
Cleanup --> End([End])
|
||||
|
||||
CheckState -->|Yes| CheckCancel{Cancel\nRequested?}
|
||||
CheckCancel -->|Yes| Cleanup
|
||||
|
||||
CheckCancel -->|No| CheckConcurrent{Under Max\nConcurrent?}
|
||||
|
||||
CheckConcurrent -->|No| WaitComplete[Wait for Task Completion]
|
||||
WaitComplete --> YieldResult[Yield Result]
|
||||
YieldResult --> CheckState
|
||||
|
||||
CheckConcurrent -->|Yes| GetNextURL[Get Next URL from Queue]
|
||||
|
||||
GetNextURL --> ValidateURL{Already\nVisited?}
|
||||
ValidateURL -->|Yes| CheckState
|
||||
|
||||
ValidateURL -->|No| ProcessURL[Process URL]
|
||||
|
||||
subgraph URL_Processing [URL Processing]
|
||||
ProcessURL --> CheckValid{URL Valid?}
|
||||
CheckValid -->|No| UpdateStats[Update Skip Stats]
|
||||
|
||||
CheckValid -->|Yes| CheckRobots{Allowed by\nrobots.txt?}
|
||||
CheckRobots -->|No| UpdateRobotStats[Update Robot Stats]
|
||||
|
||||
CheckRobots -->|Yes| ApplyDelay[Apply Politeness Delay]
|
||||
ApplyDelay --> FetchContent[Fetch Content with Rate Limit]
|
||||
|
||||
FetchContent --> CheckError{Error?}
|
||||
CheckError -->|Yes| Retry{Retry\nNeeded?}
|
||||
Retry -->|Yes| FetchContent
|
||||
Retry -->|No| UpdateFailStats[Update Fail Stats]
|
||||
|
||||
CheckError -->|No| ExtractLinks[Extract & Process Links]
|
||||
ExtractLinks --> ScoreURLs[Score New URLs]
|
||||
ScoreURLs --> AddToQueue[Add to Priority Queue]
|
||||
end
|
||||
|
||||
ProcessURL --> CreateTask{Parallel\nProcessing?}
|
||||
CreateTask -->|Yes| AddTask[Add to Pending Tasks]
|
||||
CreateTask -->|No| DirectProcess[Process Directly]
|
||||
|
||||
AddTask --> CheckState
|
||||
DirectProcess --> YieldResult
|
||||
|
||||
UpdateStats --> CheckState
|
||||
UpdateRobotStats --> CheckState
|
||||
UpdateFailStats --> CheckState
|
||||
|
||||
classDef process fill:#90caf9,stroke:#000,stroke-width:2px;
|
||||
classDef decision fill:#fff59d,stroke:#000,stroke-width:2px;
|
||||
classDef error fill:#ef9a9a,stroke:#000,stroke-width:2px;
|
||||
classDef stats fill:#a5d6a7,stroke:#000,stroke-width:2px;
|
||||
|
||||
class Start,End stats;
|
||||
class CheckState,CheckCancel,CheckConcurrent,ValidateURL,CheckValid,CheckRobots,CheckError,Retry,CreateTask decision;
|
||||
class UpdateStats,UpdateRobotStats,UpdateFailStats,InitStats,Cleanup stats;
|
||||
class ProcessURL,FetchContent,ExtractLinks,ScoreURLs process;
|
||||
```
|
||||
|
||||
## How It Works
|
||||
|
||||
The BFS strategy crawls a website by:
|
||||
1. Starting from a root URL
|
||||
2. Processing all URLs at the current depth
|
||||
3. Moving to URLs at the next depth level
|
||||
4. Continuing until maximum depth is reached
|
||||
|
||||
This ensures systematic coverage of the website while maintaining control over the crawling process.
|
||||
|
||||
## Key Features
|
||||
|
||||
### 1. Smart URL Processing
|
||||
```python
|
||||
strategy = BFSScraperStrategy(
|
||||
max_depth=2,
|
||||
filter_chain=my_filters,
|
||||
url_scorer=my_scorer,
|
||||
max_concurrent=5
|
||||
)
|
||||
```
|
||||
- Controls crawl depth
|
||||
- Filters unwanted URLs
|
||||
- Scores URLs for priority
|
||||
- Manages concurrent requests
|
||||
|
||||
### 2. Polite Crawling
|
||||
The strategy automatically implements web crawling best practices:
|
||||
- Respects robots.txt
|
||||
- Implements rate limiting
|
||||
- Adds politeness delays
|
||||
- Manages concurrent requests
|
||||
|
||||
### 3. Link Processing Control
|
||||
```python
|
||||
strategy = BFSScraperStrategy(
|
||||
...,
|
||||
process_external_links=False # Only process internal links
|
||||
)
|
||||
```
|
||||
- Control whether to follow external links
|
||||
- Default: internal links only
|
||||
- Enable external links when needed
|
||||
|
||||
## Configuration Options
|
||||
|
||||
| Parameter | Description | Default |
|
||||
|-----------|-------------|---------|
|
||||
| max_depth | Maximum crawl depth | Required |
|
||||
| filter_chain | URL filtering rules | Required |
|
||||
| url_scorer | URL priority scoring | Required |
|
||||
| max_concurrent | Max parallel requests | 5 |
|
||||
| min_crawl_delay | Seconds between requests | 1 |
|
||||
| process_external_links | Follow external links | False |
|
||||
|
||||
## Best Practices
|
||||
|
||||
1. **Set Appropriate Depth**
|
||||
- Start with smaller depths (2-3)
|
||||
- Increase based on needs
|
||||
- Consider site structure
|
||||
|
||||
2. **Configure Filters**
|
||||
- Use URL patterns
|
||||
- Filter by content type
|
||||
- Avoid unwanted sections
|
||||
|
||||
3. **Tune Performance**
|
||||
- Adjust max_concurrent
|
||||
- Set appropriate delays
|
||||
- Monitor resource usage
|
||||
|
||||
4. **Handle External Links**
|
||||
- Keep external_links=False for focused crawls
|
||||
- Enable only when needed
|
||||
- Consider additional filtering
|
||||
|
||||
## Example Usage
|
||||
|
||||
```python
|
||||
from crawl4ai.scraper import BFSScraperStrategy
|
||||
from crawl4ai.scraper.filters import FilterChain
|
||||
from crawl4ai.scraper.scorers import BasicURLScorer
|
||||
|
||||
# Configure strategy
|
||||
strategy = BFSScraperStrategy(
|
||||
max_depth=3,
|
||||
filter_chain=FilterChain([
|
||||
URLPatternFilter("*.example.com/*"),
|
||||
ContentTypeFilter(["text/html"])
|
||||
]),
|
||||
url_scorer=BasicURLScorer(),
|
||||
max_concurrent=5,
|
||||
min_crawl_delay=1,
|
||||
process_external_links=False
|
||||
)
|
||||
|
||||
# Use with AsyncWebScraper
|
||||
scraper = AsyncWebScraper(crawler, strategy)
|
||||
results = await scraper.ascrape("https://example.com")
|
||||
```
|
||||
|
||||
## Common Use Cases
|
||||
|
||||
### 1. Site Mapping
|
||||
```python
|
||||
strategy = BFSScraperStrategy(
|
||||
max_depth=5,
|
||||
filter_chain=site_filter,
|
||||
url_scorer=depth_scorer,
|
||||
process_external_links=False
|
||||
)
|
||||
```
|
||||
Perfect for creating complete site maps or understanding site structure.
|
||||
|
||||
### 2. Content Aggregation
|
||||
```python
|
||||
strategy = BFSScraperStrategy(
|
||||
max_depth=2,
|
||||
filter_chain=content_filter,
|
||||
url_scorer=relevance_scorer,
|
||||
max_concurrent=3
|
||||
)
|
||||
```
|
||||
Ideal for collecting specific types of content (articles, products, etc.).
|
||||
|
||||
### 3. Link Analysis
|
||||
```python
|
||||
strategy = BFSScraperStrategy(
|
||||
max_depth=1,
|
||||
filter_chain=link_filter,
|
||||
url_scorer=link_scorer,
|
||||
process_external_links=True
|
||||
)
|
||||
```
|
||||
Useful for analyzing both internal and external link structures.
|
||||
|
||||
## Advanced Features
|
||||
|
||||
### Progress Monitoring
|
||||
```python
|
||||
async for result in scraper.ascrape(url):
|
||||
print(f"Current depth: {strategy.stats.current_depth}")
|
||||
print(f"Processed URLs: {strategy.stats.urls_processed}")
|
||||
```
|
||||
|
||||
### Custom URL Scoring
|
||||
```python
|
||||
class CustomScorer(URLScorer):
|
||||
def score(self, url: str) -> float:
|
||||
# Lower scores = higher priority
|
||||
return score_based_on_criteria(url)
|
||||
```
|
||||
|
||||
## Troubleshooting
|
||||
|
||||
1. **Slow Crawling**
|
||||
- Increase max_concurrent
|
||||
- Adjust min_crawl_delay
|
||||
- Check network conditions
|
||||
|
||||
2. **Missing Content**
|
||||
- Verify max_depth
|
||||
- Check filter settings
|
||||
- Review URL patterns
|
||||
|
||||
3. **High Resource Usage**
|
||||
- Reduce max_concurrent
|
||||
- Increase crawl delay
|
||||
- Add more specific filters
|
||||
|
||||
342
docs/scrapper/filters_scrorers.md
Normal file
342
docs/scrapper/filters_scrorers.md
Normal file
@@ -0,0 +1,342 @@
|
||||
# URL Filters and Scorers
|
||||
|
||||
The crawl4ai library provides powerful URL filtering and scoring capabilities that help you control and prioritize your web crawling. This guide explains how to use these features effectively.
|
||||
|
||||
```mermaid
|
||||
flowchart TB
|
||||
Start([URL Input]) --> Chain[Filter Chain]
|
||||
|
||||
subgraph Chain Process
|
||||
Chain --> Pattern{URL Pattern\nFilter}
|
||||
Pattern -->|Match| Content{Content Type\nFilter}
|
||||
Pattern -->|No Match| Reject1[Reject URL]
|
||||
|
||||
Content -->|Allowed| Domain{Domain\nFilter}
|
||||
Content -->|Not Allowed| Reject2[Reject URL]
|
||||
|
||||
Domain -->|Allowed| Accept[Accept URL]
|
||||
Domain -->|Blocked| Reject3[Reject URL]
|
||||
end
|
||||
|
||||
subgraph Statistics
|
||||
Pattern --> UpdatePattern[Update Pattern Stats]
|
||||
Content --> UpdateContent[Update Content Stats]
|
||||
Domain --> UpdateDomain[Update Domain Stats]
|
||||
Accept --> UpdateChain[Update Chain Stats]
|
||||
Reject1 --> UpdateChain
|
||||
Reject2 --> UpdateChain
|
||||
Reject3 --> UpdateChain
|
||||
end
|
||||
|
||||
Accept --> End([End])
|
||||
Reject1 --> End
|
||||
Reject2 --> End
|
||||
Reject3 --> End
|
||||
|
||||
classDef process fill:#90caf9,stroke:#000,stroke-width:2px;
|
||||
classDef decision fill:#fff59d,stroke:#000,stroke-width:2px;
|
||||
classDef reject fill:#ef9a9a,stroke:#000,stroke-width:2px;
|
||||
classDef accept fill:#a5d6a7,stroke:#000,stroke-width:2px;
|
||||
|
||||
class Start,End accept;
|
||||
class Pattern,Content,Domain decision;
|
||||
class Reject1,Reject2,Reject3 reject;
|
||||
class Chain,UpdatePattern,UpdateContent,UpdateDomain,UpdateChain process;
|
||||
```
|
||||
|
||||
## URL Filters
|
||||
|
||||
URL filters help you control which URLs are crawled. Multiple filters can be chained together to create sophisticated filtering rules.
|
||||
|
||||
### Available Filters
|
||||
|
||||
1. **URL Pattern Filter**
|
||||
```python
|
||||
pattern_filter = URLPatternFilter([
|
||||
"*.example.com/*", # Glob pattern
|
||||
"*/article/*", # Path pattern
|
||||
re.compile(r"blog-\d+") # Regex pattern
|
||||
])
|
||||
```
|
||||
- Supports glob patterns and regex
|
||||
- Multiple patterns per filter
|
||||
- Pattern pre-compilation for performance
|
||||
|
||||
2. **Content Type Filter**
|
||||
```python
|
||||
content_filter = ContentTypeFilter([
|
||||
"text/html",
|
||||
"application/pdf"
|
||||
], check_extension=True)
|
||||
```
|
||||
- Filter by MIME types
|
||||
- Extension checking
|
||||
- Support for multiple content types
|
||||
|
||||
3. **Domain Filter**
|
||||
```python
|
||||
domain_filter = DomainFilter(
|
||||
allowed_domains=["example.com", "blog.example.com"],
|
||||
blocked_domains=["ads.example.com"]
|
||||
)
|
||||
```
|
||||
- Allow/block specific domains
|
||||
- Subdomain support
|
||||
- Efficient domain matching
|
||||
|
||||
### Creating Filter Chains
|
||||
|
||||
```python
|
||||
# Create and configure a filter chain
|
||||
filter_chain = FilterChain([
|
||||
URLPatternFilter(["*.example.com/*"]),
|
||||
ContentTypeFilter(["text/html"]),
|
||||
DomainFilter(blocked_domains=["ads.*"])
|
||||
])
|
||||
|
||||
# Add more filters
|
||||
filter_chain.add_filter(
|
||||
URLPatternFilter(["*/article/*"])
|
||||
)
|
||||
```
|
||||
|
||||
```mermaid
|
||||
flowchart TB
|
||||
Start([URL Input]) --> Composite[Composite Scorer]
|
||||
|
||||
subgraph Scoring Process
|
||||
Composite --> Keywords[Keyword Relevance]
|
||||
Composite --> Path[Path Depth]
|
||||
Composite --> Content[Content Type]
|
||||
Composite --> Fresh[Freshness]
|
||||
Composite --> Domain[Domain Authority]
|
||||
|
||||
Keywords --> KeywordScore[Calculate Score]
|
||||
Path --> PathScore[Calculate Score]
|
||||
Content --> ContentScore[Calculate Score]
|
||||
Fresh --> FreshScore[Calculate Score]
|
||||
Domain --> DomainScore[Calculate Score]
|
||||
|
||||
KeywordScore --> Weight1[Apply Weight]
|
||||
PathScore --> Weight2[Apply Weight]
|
||||
ContentScore --> Weight3[Apply Weight]
|
||||
FreshScore --> Weight4[Apply Weight]
|
||||
DomainScore --> Weight5[Apply Weight]
|
||||
end
|
||||
|
||||
Weight1 --> Combine[Combine Scores]
|
||||
Weight2 --> Combine
|
||||
Weight3 --> Combine
|
||||
Weight4 --> Combine
|
||||
Weight5 --> Combine
|
||||
|
||||
Combine --> Normalize{Normalize?}
|
||||
Normalize -->|Yes| NormalizeScore[Normalize Combined Score]
|
||||
Normalize -->|No| FinalScore[Final Score]
|
||||
NormalizeScore --> FinalScore
|
||||
|
||||
FinalScore --> Stats[Update Statistics]
|
||||
Stats --> End([End])
|
||||
|
||||
classDef process fill:#90caf9,stroke:#000,stroke-width:2px;
|
||||
classDef scorer fill:#fff59d,stroke:#000,stroke-width:2px;
|
||||
classDef calc fill:#a5d6a7,stroke:#000,stroke-width:2px;
|
||||
classDef decision fill:#ef9a9a,stroke:#000,stroke-width:2px;
|
||||
|
||||
class Start,End calc;
|
||||
class Keywords,Path,Content,Fresh,Domain scorer;
|
||||
class KeywordScore,PathScore,ContentScore,FreshScore,DomainScore process;
|
||||
class Normalize decision;
|
||||
```
|
||||
|
||||
## URL Scorers
|
||||
|
||||
URL scorers help prioritize which URLs to crawl first. Higher scores indicate higher priority.
|
||||
|
||||
### Available Scorers
|
||||
|
||||
1. **Keyword Relevance Scorer**
|
||||
```python
|
||||
keyword_scorer = KeywordRelevanceScorer(
|
||||
keywords=["python", "programming"],
|
||||
weight=1.0,
|
||||
case_sensitive=False
|
||||
)
|
||||
```
|
||||
- Score based on keyword matches
|
||||
- Case sensitivity options
|
||||
- Weighted scoring
|
||||
|
||||
2. **Path Depth Scorer**
|
||||
```python
|
||||
path_scorer = PathDepthScorer(
|
||||
optimal_depth=3, # Preferred URL depth
|
||||
weight=0.7
|
||||
)
|
||||
```
|
||||
- Score based on URL path depth
|
||||
- Configurable optimal depth
|
||||
- Diminishing returns for deeper paths
|
||||
|
||||
3. **Content Type Scorer**
|
||||
```python
|
||||
content_scorer = ContentTypeScorer({
|
||||
r'\.html$': 1.0,
|
||||
r'\.pdf$': 0.8,
|
||||
r'\.xml$': 0.6
|
||||
})
|
||||
```
|
||||
- Score based on file types
|
||||
- Configurable type weights
|
||||
- Pattern matching support
|
||||
|
||||
4. **Freshness Scorer**
|
||||
```python
|
||||
freshness_scorer = FreshnessScorer(weight=0.9)
|
||||
```
|
||||
- Score based on date indicators in URLs
|
||||
- Multiple date format support
|
||||
- Recency weighting
|
||||
|
||||
5. **Domain Authority Scorer**
|
||||
```python
|
||||
authority_scorer = DomainAuthorityScorer({
|
||||
"python.org": 1.0,
|
||||
"github.com": 0.9,
|
||||
"medium.com": 0.7
|
||||
})
|
||||
```
|
||||
- Score based on domain importance
|
||||
- Configurable domain weights
|
||||
- Default weight for unknown domains
|
||||
|
||||
### Combining Scorers
|
||||
|
||||
```python
|
||||
# Create a composite scorer
|
||||
composite_scorer = CompositeScorer([
|
||||
KeywordRelevanceScorer(["python"], weight=1.0),
|
||||
PathDepthScorer(optimal_depth=2, weight=0.7),
|
||||
FreshnessScorer(weight=0.8)
|
||||
], normalize=True)
|
||||
```
|
||||
|
||||
## Best Practices
|
||||
|
||||
### Filter Configuration
|
||||
|
||||
1. **Start Restrictive**
|
||||
```python
|
||||
# Begin with strict filters
|
||||
filter_chain = FilterChain([
|
||||
DomainFilter(allowed_domains=["example.com"]),
|
||||
ContentTypeFilter(["text/html"])
|
||||
])
|
||||
```
|
||||
|
||||
2. **Layer Filters**
|
||||
```python
|
||||
# Add more specific filters
|
||||
filter_chain.add_filter(
|
||||
URLPatternFilter(["*/article/*", "*/blog/*"])
|
||||
)
|
||||
```
|
||||
|
||||
3. **Monitor Filter Statistics**
|
||||
```python
|
||||
# Check filter performance
|
||||
for filter in filter_chain.filters:
|
||||
print(f"{filter.name}: {filter.stats.rejected_urls} rejected")
|
||||
```
|
||||
|
||||
### Scorer Configuration
|
||||
|
||||
1. **Balance Weights**
|
||||
```python
|
||||
# Balanced scoring configuration
|
||||
scorer = create_balanced_scorer()
|
||||
```
|
||||
|
||||
2. **Customize for Content**
|
||||
```python
|
||||
# News site configuration
|
||||
news_scorer = CompositeScorer([
|
||||
KeywordRelevanceScorer(["news", "article"], weight=1.0),
|
||||
FreshnessScorer(weight=1.0),
|
||||
PathDepthScorer(optimal_depth=2, weight=0.5)
|
||||
])
|
||||
```
|
||||
|
||||
3. **Monitor Scoring Statistics**
|
||||
```python
|
||||
# Check scoring distribution
|
||||
print(f"Average score: {scorer.stats.average_score}")
|
||||
print(f"Score range: {scorer.stats.min_score} - {scorer.stats.max_score}")
|
||||
```
|
||||
|
||||
## Common Use Cases
|
||||
|
||||
### Blog Crawling
|
||||
```python
|
||||
blog_config = {
|
||||
'filters': FilterChain([
|
||||
URLPatternFilter(["*/blog/*", "*/post/*"]),
|
||||
ContentTypeFilter(["text/html"])
|
||||
]),
|
||||
'scorer': CompositeScorer([
|
||||
FreshnessScorer(weight=1.0),
|
||||
KeywordRelevanceScorer(["blog", "article"], weight=0.8)
|
||||
])
|
||||
}
|
||||
```
|
||||
|
||||
### Documentation Sites
|
||||
```python
|
||||
docs_config = {
|
||||
'filters': FilterChain([
|
||||
URLPatternFilter(["*/docs/*", "*/guide/*"]),
|
||||
ContentTypeFilter(["text/html", "application/pdf"])
|
||||
]),
|
||||
'scorer': CompositeScorer([
|
||||
PathDepthScorer(optimal_depth=3, weight=1.0),
|
||||
KeywordRelevanceScorer(["guide", "tutorial"], weight=0.9)
|
||||
])
|
||||
}
|
||||
```
|
||||
|
||||
### E-commerce Sites
|
||||
```python
|
||||
ecommerce_config = {
|
||||
'filters': FilterChain([
|
||||
URLPatternFilter(["*/product/*", "*/category/*"]),
|
||||
DomainFilter(blocked_domains=["ads.*", "tracker.*"])
|
||||
]),
|
||||
'scorer': CompositeScorer([
|
||||
PathDepthScorer(optimal_depth=2, weight=1.0),
|
||||
ContentTypeScorer({
|
||||
r'/product/': 1.0,
|
||||
r'/category/': 0.8
|
||||
})
|
||||
])
|
||||
}
|
||||
```
|
||||
|
||||
## Advanced Topics
|
||||
|
||||
### Custom Filters
|
||||
```python
|
||||
class CustomFilter(URLFilter):
|
||||
def apply(self, url: str) -> bool:
|
||||
# Your custom filtering logic
|
||||
return True
|
||||
```
|
||||
|
||||
### Custom Scorers
|
||||
```python
|
||||
class CustomScorer(URLScorer):
|
||||
def _calculate_score(self, url: str) -> float:
|
||||
# Your custom scoring logic
|
||||
return 1.0
|
||||
```
|
||||
|
||||
For more examples, check our [example repository](https://github.com/example/crawl4ai/examples).
|
||||
206
docs/scrapper/how_to_use.md
Normal file
206
docs/scrapper/how_to_use.md
Normal file
@@ -0,0 +1,206 @@
|
||||
# Scraper Examples Guide
|
||||
|
||||
This guide provides two complete examples of using the crawl4ai scraper: a basic implementation for simple use cases and an advanced implementation showcasing all features.
|
||||
|
||||
## Basic Example
|
||||
|
||||
The basic example demonstrates a simple blog scraping scenario:
|
||||
|
||||
```python
|
||||
from crawl4ai.scraper import AsyncWebScraper, BFSScraperStrategy, FilterChain
|
||||
|
||||
# Create simple filter chain
|
||||
filter_chain = FilterChain([
|
||||
URLPatternFilter("*/blog/*"),
|
||||
ContentTypeFilter(["text/html"])
|
||||
])
|
||||
|
||||
# Initialize strategy
|
||||
strategy = BFSScraperStrategy(
|
||||
max_depth=2,
|
||||
filter_chain=filter_chain,
|
||||
url_scorer=None,
|
||||
max_concurrent=3
|
||||
)
|
||||
|
||||
# Create and run scraper
|
||||
crawler = AsyncWebCrawler()
|
||||
scraper = AsyncWebScraper(crawler, strategy)
|
||||
result = await scraper.ascrape("https://example.com/blog/")
|
||||
```
|
||||
|
||||
### Features Demonstrated
|
||||
- Basic URL filtering
|
||||
- Simple content type filtering
|
||||
- Depth control
|
||||
- Concurrent request limiting
|
||||
- Result collection
|
||||
|
||||
## Advanced Example
|
||||
|
||||
The advanced example shows a sophisticated news site scraping setup with all features enabled:
|
||||
|
||||
```python
|
||||
# Create comprehensive filter chain
|
||||
filter_chain = FilterChain([
|
||||
DomainFilter(
|
||||
allowed_domains=["example.com"],
|
||||
blocked_domains=["ads.example.com"]
|
||||
),
|
||||
URLPatternFilter([
|
||||
"*/article/*",
|
||||
re.compile(r"\d{4}/\d{2}/.*")
|
||||
]),
|
||||
ContentTypeFilter(["text/html"])
|
||||
])
|
||||
|
||||
# Create intelligent scorer
|
||||
scorer = CompositeScorer([
|
||||
KeywordRelevanceScorer(
|
||||
keywords=["news", "breaking"],
|
||||
weight=1.0
|
||||
),
|
||||
PathDepthScorer(optimal_depth=3, weight=0.7),
|
||||
FreshnessScorer(weight=0.9)
|
||||
])
|
||||
|
||||
# Initialize advanced strategy
|
||||
strategy = BFSScraperStrategy(
|
||||
max_depth=4,
|
||||
filter_chain=filter_chain,
|
||||
url_scorer=scorer,
|
||||
max_concurrent=5
|
||||
)
|
||||
```
|
||||
|
||||
### Features Demonstrated
|
||||
1. **Advanced Filtering**
|
||||
- Domain filtering
|
||||
- Pattern matching
|
||||
- Content type control
|
||||
|
||||
2. **Intelligent Scoring**
|
||||
- Keyword relevance
|
||||
- Path optimization
|
||||
- Freshness priority
|
||||
|
||||
3. **Monitoring**
|
||||
- Progress tracking
|
||||
- Error handling
|
||||
- Statistics collection
|
||||
|
||||
4. **Resource Management**
|
||||
- Concurrent processing
|
||||
- Rate limiting
|
||||
- Cleanup handling
|
||||
|
||||
## Running the Examples
|
||||
|
||||
```bash
|
||||
# Basic usage
|
||||
python basic_scraper_example.py
|
||||
|
||||
# Advanced usage with logging
|
||||
PYTHONPATH=. python advanced_scraper_example.py
|
||||
```
|
||||
|
||||
## Example Output
|
||||
|
||||
### Basic Example
|
||||
```
|
||||
Crawled 15 pages:
|
||||
- https://example.com/blog/post1: 24560 bytes
|
||||
- https://example.com/blog/post2: 18920 bytes
|
||||
...
|
||||
```
|
||||
|
||||
### Advanced Example
|
||||
```
|
||||
INFO: Starting crawl of https://example.com/news/
|
||||
INFO: Processed: https://example.com/news/breaking/story1
|
||||
DEBUG: KeywordScorer: 0.85
|
||||
DEBUG: FreshnessScorer: 0.95
|
||||
INFO: Progress: 10 URLs processed
|
||||
...
|
||||
INFO: Scraping completed:
|
||||
INFO: - URLs processed: 50
|
||||
INFO: - Errors: 2
|
||||
INFO: - Total content size: 1240.50 KB
|
||||
```
|
||||
|
||||
## Customization
|
||||
|
||||
### Adding Custom Filters
|
||||
```python
|
||||
class CustomFilter(URLFilter):
|
||||
def apply(self, url: str) -> bool:
|
||||
# Your custom filtering logic
|
||||
return True
|
||||
|
||||
filter_chain.add_filter(CustomFilter())
|
||||
```
|
||||
|
||||
### Custom Scoring Logic
|
||||
```python
|
||||
class CustomScorer(URLScorer):
|
||||
def _calculate_score(self, url: str) -> float:
|
||||
# Your custom scoring logic
|
||||
return 1.0
|
||||
|
||||
scorer = CompositeScorer([
|
||||
CustomScorer(weight=1.0),
|
||||
...
|
||||
])
|
||||
```
|
||||
|
||||
## Best Practices
|
||||
|
||||
1. **Start Simple**
|
||||
- Begin with basic filtering
|
||||
- Add features incrementally
|
||||
- Test thoroughly at each step
|
||||
|
||||
2. **Monitor Performance**
|
||||
- Watch memory usage
|
||||
- Track processing times
|
||||
- Adjust concurrency as needed
|
||||
|
||||
3. **Handle Errors**
|
||||
- Implement proper error handling
|
||||
- Log important events
|
||||
- Track error statistics
|
||||
|
||||
4. **Optimize Resources**
|
||||
- Set appropriate delays
|
||||
- Limit concurrent requests
|
||||
- Use streaming for large crawls
|
||||
|
||||
## Troubleshooting
|
||||
|
||||
Common issues and solutions:
|
||||
|
||||
1. **Too Many Requests**
|
||||
```python
|
||||
strategy = BFSScraperStrategy(
|
||||
max_concurrent=3, # Reduce concurrent requests
|
||||
min_crawl_delay=2 # Increase delay between requests
|
||||
)
|
||||
```
|
||||
|
||||
2. **Memory Issues**
|
||||
```python
|
||||
# Use streaming mode for large crawls
|
||||
async for result in scraper.ascrape(url, stream=True):
|
||||
process_result(result)
|
||||
```
|
||||
|
||||
3. **Missing Content**
|
||||
```python
|
||||
# Check your filter chain
|
||||
filter_chain = FilterChain([
|
||||
URLPatternFilter("*"), # Broaden patterns
|
||||
ContentTypeFilter(["*"]) # Accept all content
|
||||
])
|
||||
```
|
||||
|
||||
For more examples and use cases, visit our [GitHub repository](https://github.com/example/crawl4ai/examples).
|
||||
184
docs/scrapper/scraper_quickstart.py
Normal file
184
docs/scrapper/scraper_quickstart.py
Normal file
@@ -0,0 +1,184 @@
|
||||
# basic_scraper_example.py
|
||||
from crawl4ai.scraper import (
|
||||
AsyncWebScraper,
|
||||
BFSScraperStrategy,
|
||||
FilterChain,
|
||||
URLPatternFilter,
|
||||
ContentTypeFilter
|
||||
)
|
||||
from crawl4ai.async_webcrawler import AsyncWebCrawler
|
||||
|
||||
async def basic_scraper_example():
|
||||
"""
|
||||
Basic example: Scrape a blog site for articles
|
||||
- Crawls only HTML pages
|
||||
- Stays within the blog section
|
||||
- Collects all results at once
|
||||
"""
|
||||
# Create a simple filter chain
|
||||
filter_chain = FilterChain([
|
||||
# Only crawl pages within the blog section
|
||||
URLPatternFilter("*/blog/*"),
|
||||
# Only process HTML pages
|
||||
ContentTypeFilter(["text/html"])
|
||||
])
|
||||
|
||||
# Initialize the strategy with basic configuration
|
||||
strategy = BFSScraperStrategy(
|
||||
max_depth=2, # Only go 2 levels deep
|
||||
filter_chain=filter_chain,
|
||||
url_scorer=None, # Use default scoring
|
||||
max_concurrent=3 # Limit concurrent requests
|
||||
)
|
||||
|
||||
# Create the crawler and scraper
|
||||
crawler = AsyncWebCrawler()
|
||||
scraper = AsyncWebScraper(crawler, strategy)
|
||||
|
||||
# Start scraping
|
||||
try:
|
||||
result = await scraper.ascrape("https://example.com/blog/")
|
||||
|
||||
# Process results
|
||||
print(f"Crawled {len(result.crawled_urls)} pages:")
|
||||
for url, data in result.extracted_data.items():
|
||||
print(f"- {url}: {len(data.html)} bytes")
|
||||
|
||||
except Exception as e:
|
||||
print(f"Error during scraping: {e}")
|
||||
|
||||
# advanced_scraper_example.py
|
||||
import logging
|
||||
from crawl4ai.scraper import (
|
||||
AsyncWebScraper,
|
||||
BFSScraperStrategy,
|
||||
FilterChain,
|
||||
URLPatternFilter,
|
||||
ContentTypeFilter,
|
||||
DomainFilter,
|
||||
KeywordRelevanceScorer,
|
||||
PathDepthScorer,
|
||||
FreshnessScorer,
|
||||
CompositeScorer
|
||||
)
|
||||
from crawl4ai.async_webcrawler import AsyncWebCrawler
|
||||
|
||||
async def advanced_scraper_example():
|
||||
"""
|
||||
Advanced example: Intelligent news site scraping
|
||||
- Uses all filter types
|
||||
- Implements sophisticated scoring
|
||||
- Streams results
|
||||
- Includes monitoring and logging
|
||||
"""
|
||||
# Set up logging
|
||||
logging.basicConfig(level=logging.INFO)
|
||||
logger = logging.getLogger("advanced_scraper")
|
||||
|
||||
# Create sophisticated filter chain
|
||||
filter_chain = FilterChain([
|
||||
# Domain control
|
||||
DomainFilter(
|
||||
allowed_domains=["example.com", "blog.example.com"],
|
||||
blocked_domains=["ads.example.com", "tracker.example.com"]
|
||||
),
|
||||
# URL patterns
|
||||
URLPatternFilter([
|
||||
"*/article/*",
|
||||
"*/news/*",
|
||||
"*/blog/*",
|
||||
re.compile(r"\d{4}/\d{2}/.*") # Date-based URLs
|
||||
]),
|
||||
# Content types
|
||||
ContentTypeFilter([
|
||||
"text/html",
|
||||
"application/xhtml+xml"
|
||||
])
|
||||
])
|
||||
|
||||
# Create composite scorer
|
||||
scorer = CompositeScorer([
|
||||
# Prioritize by keywords
|
||||
KeywordRelevanceScorer(
|
||||
keywords=["news", "breaking", "update", "latest"],
|
||||
weight=1.0
|
||||
),
|
||||
# Prefer optimal URL structure
|
||||
PathDepthScorer(
|
||||
optimal_depth=3,
|
||||
weight=0.7
|
||||
),
|
||||
# Prioritize fresh content
|
||||
FreshnessScorer(weight=0.9)
|
||||
])
|
||||
|
||||
# Initialize strategy with advanced configuration
|
||||
strategy = BFSScraperStrategy(
|
||||
max_depth=4,
|
||||
filter_chain=filter_chain,
|
||||
url_scorer=scorer,
|
||||
max_concurrent=5,
|
||||
min_crawl_delay=1
|
||||
)
|
||||
|
||||
# Create crawler and scraper
|
||||
crawler = AsyncWebCrawler()
|
||||
scraper = AsyncWebScraper(crawler, strategy)
|
||||
|
||||
# Track statistics
|
||||
stats = {
|
||||
'processed': 0,
|
||||
'errors': 0,
|
||||
'total_size': 0
|
||||
}
|
||||
|
||||
try:
|
||||
# Use streaming mode
|
||||
async for result in scraper.ascrape("https://example.com/news/", stream=True):
|
||||
stats['processed'] += 1
|
||||
|
||||
if result.success:
|
||||
stats['total_size'] += len(result.html)
|
||||
logger.info(f"Processed: {result.url}")
|
||||
|
||||
# Print scoring information
|
||||
for scorer_name, score in result.scores.items():
|
||||
logger.debug(f"{scorer_name}: {score:.2f}")
|
||||
else:
|
||||
stats['errors'] += 1
|
||||
logger.error(f"Failed to process {result.url}: {result.error_message}")
|
||||
|
||||
# Log progress regularly
|
||||
if stats['processed'] % 10 == 0:
|
||||
logger.info(f"Progress: {stats['processed']} URLs processed")
|
||||
|
||||
except Exception as e:
|
||||
logger.error(f"Scraping error: {e}")
|
||||
|
||||
finally:
|
||||
# Print final statistics
|
||||
logger.info("Scraping completed:")
|
||||
logger.info(f"- URLs processed: {stats['processed']}")
|
||||
logger.info(f"- Errors: {stats['errors']}")
|
||||
logger.info(f"- Total content size: {stats['total_size'] / 1024:.2f} KB")
|
||||
|
||||
# Print filter statistics
|
||||
for filter_ in filter_chain.filters:
|
||||
logger.info(f"{filter_.name} stats:")
|
||||
logger.info(f"- Passed: {filter_.stats.passed_urls}")
|
||||
logger.info(f"- Rejected: {filter_.stats.rejected_urls}")
|
||||
|
||||
# Print scorer statistics
|
||||
logger.info("Scoring statistics:")
|
||||
logger.info(f"- Average score: {scorer.stats.average_score:.2f}")
|
||||
logger.info(f"- Score range: {scorer.stats.min_score:.2f} - {scorer.stats.max_score:.2f}")
|
||||
|
||||
if __name__ == "__main__":
|
||||
import asyncio
|
||||
|
||||
# Run basic example
|
||||
print("Running basic scraper example...")
|
||||
asyncio.run(basic_scraper_example())
|
||||
|
||||
print("\nRunning advanced scraper example...")
|
||||
asyncio.run(advanced_scraper_example())
|
||||
184
tests/test_scraper.py
Normal file
184
tests/test_scraper.py
Normal file
@@ -0,0 +1,184 @@
|
||||
# basic_scraper_example.py
|
||||
from crawl4ai.scraper import (
|
||||
AsyncWebScraper,
|
||||
BFSScraperStrategy,
|
||||
FilterChain,
|
||||
URLPatternFilter,
|
||||
ContentTypeFilter
|
||||
)
|
||||
from crawl4ai.async_webcrawler import AsyncWebCrawler
|
||||
|
||||
async def basic_scraper_example():
|
||||
"""
|
||||
Basic example: Scrape a blog site for articles
|
||||
- Crawls only HTML pages
|
||||
- Stays within the blog section
|
||||
- Collects all results at once
|
||||
"""
|
||||
# Create a simple filter chain
|
||||
filter_chain = FilterChain([
|
||||
# Only crawl pages within the blog section
|
||||
URLPatternFilter("*/blog/*"),
|
||||
# Only process HTML pages
|
||||
ContentTypeFilter(["text/html"])
|
||||
])
|
||||
|
||||
# Initialize the strategy with basic configuration
|
||||
strategy = BFSScraperStrategy(
|
||||
max_depth=2, # Only go 2 levels deep
|
||||
filter_chain=filter_chain,
|
||||
url_scorer=None, # Use default scoring
|
||||
max_concurrent=3 # Limit concurrent requests
|
||||
)
|
||||
|
||||
# Create the crawler and scraper
|
||||
crawler = AsyncWebCrawler()
|
||||
scraper = AsyncWebScraper(crawler, strategy)
|
||||
|
||||
# Start scraping
|
||||
try:
|
||||
result = await scraper.ascrape("https://example.com/blog/")
|
||||
|
||||
# Process results
|
||||
print(f"Crawled {len(result.crawled_urls)} pages:")
|
||||
for url, data in result.extracted_data.items():
|
||||
print(f"- {url}: {len(data.html)} bytes")
|
||||
|
||||
except Exception as e:
|
||||
print(f"Error during scraping: {e}")
|
||||
|
||||
# advanced_scraper_example.py
|
||||
import logging
|
||||
from crawl4ai.scraper import (
|
||||
AsyncWebScraper,
|
||||
BFSScraperStrategy,
|
||||
FilterChain,
|
||||
URLPatternFilter,
|
||||
ContentTypeFilter,
|
||||
DomainFilter,
|
||||
KeywordRelevanceScorer,
|
||||
PathDepthScorer,
|
||||
FreshnessScorer,
|
||||
CompositeScorer
|
||||
)
|
||||
from crawl4ai.async_webcrawler import AsyncWebCrawler
|
||||
|
||||
async def advanced_scraper_example():
|
||||
"""
|
||||
Advanced example: Intelligent news site scraping
|
||||
- Uses all filter types
|
||||
- Implements sophisticated scoring
|
||||
- Streams results
|
||||
- Includes monitoring and logging
|
||||
"""
|
||||
# Set up logging
|
||||
logging.basicConfig(level=logging.INFO)
|
||||
logger = logging.getLogger("advanced_scraper")
|
||||
|
||||
# Create sophisticated filter chain
|
||||
filter_chain = FilterChain([
|
||||
# Domain control
|
||||
DomainFilter(
|
||||
allowed_domains=["example.com", "blog.example.com"],
|
||||
blocked_domains=["ads.example.com", "tracker.example.com"]
|
||||
),
|
||||
# URL patterns
|
||||
URLPatternFilter([
|
||||
"*/article/*",
|
||||
"*/news/*",
|
||||
"*/blog/*",
|
||||
re.compile(r"\d{4}/\d{2}/.*") # Date-based URLs
|
||||
]),
|
||||
# Content types
|
||||
ContentTypeFilter([
|
||||
"text/html",
|
||||
"application/xhtml+xml"
|
||||
])
|
||||
])
|
||||
|
||||
# Create composite scorer
|
||||
scorer = CompositeScorer([
|
||||
# Prioritize by keywords
|
||||
KeywordRelevanceScorer(
|
||||
keywords=["news", "breaking", "update", "latest"],
|
||||
weight=1.0
|
||||
),
|
||||
# Prefer optimal URL structure
|
||||
PathDepthScorer(
|
||||
optimal_depth=3,
|
||||
weight=0.7
|
||||
),
|
||||
# Prioritize fresh content
|
||||
FreshnessScorer(weight=0.9)
|
||||
])
|
||||
|
||||
# Initialize strategy with advanced configuration
|
||||
strategy = BFSScraperStrategy(
|
||||
max_depth=4,
|
||||
filter_chain=filter_chain,
|
||||
url_scorer=scorer,
|
||||
max_concurrent=5,
|
||||
min_crawl_delay=1
|
||||
)
|
||||
|
||||
# Create crawler and scraper
|
||||
crawler = AsyncWebCrawler()
|
||||
scraper = AsyncWebScraper(crawler, strategy)
|
||||
|
||||
# Track statistics
|
||||
stats = {
|
||||
'processed': 0,
|
||||
'errors': 0,
|
||||
'total_size': 0
|
||||
}
|
||||
|
||||
try:
|
||||
# Use streaming mode
|
||||
async for result in scraper.ascrape("https://example.com/news/", stream=True):
|
||||
stats['processed'] += 1
|
||||
|
||||
if result.success:
|
||||
stats['total_size'] += len(result.html)
|
||||
logger.info(f"Processed: {result.url}")
|
||||
|
||||
# Print scoring information
|
||||
for scorer_name, score in result.scores.items():
|
||||
logger.debug(f"{scorer_name}: {score:.2f}")
|
||||
else:
|
||||
stats['errors'] += 1
|
||||
logger.error(f"Failed to process {result.url}: {result.error_message}")
|
||||
|
||||
# Log progress regularly
|
||||
if stats['processed'] % 10 == 0:
|
||||
logger.info(f"Progress: {stats['processed']} URLs processed")
|
||||
|
||||
except Exception as e:
|
||||
logger.error(f"Scraping error: {e}")
|
||||
|
||||
finally:
|
||||
# Print final statistics
|
||||
logger.info("Scraping completed:")
|
||||
logger.info(f"- URLs processed: {stats['processed']}")
|
||||
logger.info(f"- Errors: {stats['errors']}")
|
||||
logger.info(f"- Total content size: {stats['total_size'] / 1024:.2f} KB")
|
||||
|
||||
# Print filter statistics
|
||||
for filter_ in filter_chain.filters:
|
||||
logger.info(f"{filter_.name} stats:")
|
||||
logger.info(f"- Passed: {filter_.stats.passed_urls}")
|
||||
logger.info(f"- Rejected: {filter_.stats.rejected_urls}")
|
||||
|
||||
# Print scorer statistics
|
||||
logger.info("Scoring statistics:")
|
||||
logger.info(f"- Average score: {scorer.stats.average_score:.2f}")
|
||||
logger.info(f"- Score range: {scorer.stats.min_score:.2f} - {scorer.stats.max_score:.2f}")
|
||||
|
||||
if __name__ == "__main__":
|
||||
import asyncio
|
||||
|
||||
# Run basic example
|
||||
print("Running basic scraper example...")
|
||||
asyncio.run(basic_scraper_example())
|
||||
|
||||
print("\nRunning advanced scraper example...")
|
||||
asyncio.run(advanced_scraper_example())
|
||||
Reference in New Issue
Block a user