Files
crawl4ai/crawl4ai/content_scraping_strategy.py
UncleCode 24723b2f10 Enhance features and documentation
- Updated version to 0.3.743
  - Improved ManagedBrowser configuration with dynamic host/port
  - Implemented fast HTML formatting in web crawler
  - Enhanced markdown generation with a new generator class
  - Improved sanitization and utility functions
  - Added contributor details and pull request acknowledgments
  - Updated documentation for clearer usage scenarios
  - Adjusted tests to reflect class name changes
2024-11-28 12:45:05 +08:00

688 lines
29 KiB
Python

import re # Point 1: Pre-Compile Regular Expressions
from abc import ABC, abstractmethod
from typing import Dict, Any, Optional
from bs4 import BeautifulSoup
from concurrent.futures import ThreadPoolExecutor
import asyncio, requests, re, os
from .config import *
from bs4 import element, NavigableString, Comment
from urllib.parse import urljoin
from requests.exceptions import InvalidSchema
# from .content_cleaning_strategy import ContentCleaningStrategy
from .content_filter_strategy import RelevantContentFilter, BM25ContentFilter#, HeuristicContentFilter
from .markdown_generation_strategy import MarkdownGenerationStrategy, DefaultMarkdownGenerator
from .models import MarkdownGenerationResult
from .utils import (
sanitize_input_encode,
sanitize_html,
extract_metadata,
InvalidCSSSelectorError,
CustomHTML2Text,
normalize_url,
is_external_url
)
from .tools import profile_and_time
# Pre-compile regular expressions for Open Graph and Twitter metadata
OG_REGEX = re.compile(r'^og:')
TWITTER_REGEX = re.compile(r'^twitter:')
DIMENSION_REGEX = re.compile(r"(\d+)(\D*)")
# Function to parse image height/width value and units
def parse_dimension(dimension):
if dimension:
# match = re.match(r"(\d+)(\D*)", dimension)
match = DIMENSION_REGEX.match(dimension)
if match:
number = int(match.group(1))
unit = match.group(2) or 'px' # Default unit is 'px' if not specified
return number, unit
return None, None
# Fetch image file metadata to extract size and extension
def fetch_image_file_size(img, base_url):
#If src is relative path construct full URL, if not it may be CDN URL
img_url = urljoin(base_url,img.get('src'))
try:
response = requests.head(img_url)
if response.status_code == 200:
return response.headers.get('Content-Length',None)
else:
print(f"Failed to retrieve file size for {img_url}")
return None
except InvalidSchema as e:
return None
finally:
return
class ContentScrapingStrategy(ABC):
@abstractmethod
def scrap(self, url: str, html: str, **kwargs) -> Dict[str, Any]:
pass
@abstractmethod
async def ascrap(self, url: str, html: str, **kwargs) -> Dict[str, Any]:
pass
class WebScrapingStrategy(ContentScrapingStrategy):
def __init__(self, logger=None):
self.logger = logger
def _log(self, level, message, tag="SCRAPE", **kwargs):
"""Helper method to safely use logger."""
if self.logger:
log_method = getattr(self.logger, level)
log_method(message=message, tag=tag, **kwargs)
def scrap(self, url: str, html: str, **kwargs) -> Dict[str, Any]:
return self._get_content_of_website_optimized(url, html, is_async=False, **kwargs)
async def ascrap(self, url: str, html: str, **kwargs) -> Dict[str, Any]:
return await asyncio.to_thread(self._get_content_of_website_optimized, url, html, **kwargs)
def _generate_markdown_content(self,
cleaned_html: str,
html: str,
url: str,
success: bool,
**kwargs) -> Dict[str, Any]:
"""Generate markdown content using either new strategy or legacy method.
Args:
cleaned_html: Sanitized HTML content
html: Original HTML content
url: Base URL of the page
success: Whether scraping was successful
**kwargs: Additional options including:
- markdown_generator: Optional[MarkdownGenerationStrategy]
- html2text: Dict[str, Any] options for HTML2Text
- content_filter: Optional[RelevantContentFilter]
- fit_markdown: bool
- fit_markdown_user_query: Optional[str]
- fit_markdown_bm25_threshold: float
Returns:
Dict containing markdown content in various formats
"""
markdown_generator: Optional[MarkdownGenerationStrategy] = kwargs.get('markdown_generator', DefaultMarkdownGenerator())
if markdown_generator:
try:
if kwargs.get('fit_markdown', False) and not markdown_generator.content_filter:
markdown_generator.content_filter = BM25ContentFilter(
user_query=kwargs.get('fit_markdown_user_query', None),
bm25_threshold=kwargs.get('fit_markdown_bm25_threshold', 1.0)
)
markdown_result: MarkdownGenerationResult = markdown_generator.generate_markdown(
cleaned_html=cleaned_html,
base_url=url,
html2text_options=kwargs.get('html2text', {})
)
help_message = """"""
return {
'markdown': markdown_result.raw_markdown,
'fit_markdown': markdown_result.fit_markdown,
'fit_html': markdown_result.fit_html,
'markdown_v2': markdown_result
}
except Exception as e:
self._log('error',
message="Error using new markdown generation strategy: {error}",
tag="SCRAPE",
params={"error": str(e)}
)
markdown_generator = None
return {
'markdown': f"Error using new markdown generation strategy: {str(e)}",
'fit_markdown': "Set flag 'fit_markdown' to True to get cleaned HTML content.",
'fit_html': "Set flag 'fit_markdown' to True to get cleaned HTML content.",
'markdown_v2': None
}
# Legacy method
h = CustomHTML2Text()
h.update_params(**kwargs.get('html2text', {}))
markdown = h.handle(cleaned_html)
markdown = markdown.replace(' ```', '```')
fit_markdown = "Set flag 'fit_markdown' to True to get cleaned HTML content."
fit_html = "Set flag 'fit_markdown' to True to get cleaned HTML content."
if kwargs.get('content_filter', None) or kwargs.get('fit_markdown', False):
content_filter = kwargs.get('content_filter', None)
if not content_filter:
content_filter = BM25ContentFilter(
user_query=kwargs.get('fit_markdown_user_query', None),
bm25_threshold=kwargs.get('fit_markdown_bm25_threshold', 1.0)
)
fit_html = content_filter.filter_content(html)
fit_html = '\n'.join('<div>{}</div>'.format(s) for s in fit_html)
fit_markdown = h.handle(fit_html)
markdown_v2 = MarkdownGenerationResult(
raw_markdown=markdown,
markdown_with_citations=markdown,
references_markdown=markdown,
fit_markdown=fit_markdown
)
return {
'markdown': markdown,
'fit_markdown': fit_markdown,
'fit_html': fit_html,
'markdown_v2' : markdown_v2
}
def _get_content_of_website_optimized(self, url: str, html: str, word_count_threshold: int = MIN_WORD_THRESHOLD, css_selector: str = None, **kwargs) -> Dict[str, Any]:
success = True
if not html:
return None
# soup = BeautifulSoup(html, 'html.parser')
soup = BeautifulSoup(html, 'lxml')
body = soup.body
try:
meta = extract_metadata("", soup)
except Exception as e:
self._log('error',
message="Error extracting metadata: {error}",
tag="SCRAPE",
params={"error": str(e)}
)
# print('Error extracting metadata:', str(e))
meta = {}
image_description_min_word_threshold = kwargs.get('image_description_min_word_threshold', IMAGE_DESCRIPTION_MIN_WORD_THRESHOLD)
for tag in kwargs.get('excluded_tags', []) or []:
for el in body.select(tag):
el.decompose()
if css_selector:
selected_elements = body.select(css_selector)
if not selected_elements:
return {
'markdown': '',
'cleaned_html': '',
'success': True,
'media': {'images': [], 'videos': [], 'audios': []},
'links': {'internal': [], 'external': []},
'metadata': {},
'message': f"No elements found for CSS selector: {css_selector}"
}
# raise InvalidCSSSelectorError(f"Invalid CSS selector, No elements found for CSS selector: {css_selector}")
body = soup.new_tag('div')
for el in selected_elements:
body.append(el)
links = {'internal': [], 'external': []}
media = {'images': [], 'videos': [], 'audios': []}
internal_links_dict = {}
external_links_dict = {}
# Extract meaningful text for media files from closest parent
def find_closest_parent_with_useful_text(tag):
current_tag = tag
while current_tag:
current_tag = current_tag.parent
# Get the text content of the parent tag
if current_tag:
text_content = current_tag.get_text(separator=' ',strip=True)
# Check if the text content has at least word_count_threshold
if len(text_content.split()) >= image_description_min_word_threshold:
return text_content
return None
def process_image_old(img, url, index, total_images):
#Check if an image has valid display and inside undesired html elements
def is_valid_image(img, parent, parent_classes):
style = img.get('style', '')
src = img.get('src', '')
classes_to_check = ['button', 'icon', 'logo']
tags_to_check = ['button', 'input']
return all([
'display:none' not in style,
src,
not any(s in var for var in [src, img.get('alt', ''), *parent_classes] for s in classes_to_check),
parent.name not in tags_to_check
])
#Score an image for it's usefulness
def score_image_for_usefulness(img, base_url, index, images_count):
image_height = img.get('height')
height_value, height_unit = parse_dimension(image_height)
image_width = img.get('width')
width_value, width_unit = parse_dimension(image_width)
image_size = 0 #int(fetch_image_file_size(img,base_url) or 0)
image_src = img.get('src','')
if "data:image/" in image_src:
image_format = image_src.split(',')[0].split(';')[0].split('/')[1]
else:
image_format = os.path.splitext(img.get('src',''))[1].lower()
# Remove . from format
image_format = image_format.strip('.').split('?')[0]
score = 0
if height_value:
if height_unit == 'px' and height_value > 150:
score += 1
if height_unit in ['%','vh','vmin','vmax'] and height_value >30:
score += 1
if width_value:
if width_unit == 'px' and width_value > 150:
score += 1
if width_unit in ['%','vh','vmin','vmax'] and width_value >30:
score += 1
if image_size > 10000:
score += 1
if img.get('alt') != '':
score+=1
if any(image_format==format for format in ['jpg','png','webp']):
score+=1
if index/images_count<0.5:
score+=1
return score
if not is_valid_image(img, img.parent, img.parent.get('class', [])):
return None
score = score_image_for_usefulness(img, url, index, total_images)
if score <= kwargs.get('image_score_threshold', IMAGE_SCORE_THRESHOLD):
return None
base_result = {
'src': img.get('src', ''),
'data-src': img.get('data-src', ''),
'alt': img.get('alt', ''),
'desc': find_closest_parent_with_useful_text(img),
'score': score,
'type': 'image'
}
sources = []
srcset = img.get('srcset', '')
if srcset:
sources = parse_srcset(srcset)
if sources:
return [dict(base_result, src=source['url'], width=source['width'])
for source in sources]
return [base_result] # Always return a list
def process_image(img, url, index, total_images):
parse_srcset = lambda s: [{'url': u.strip().split()[0], 'width': u.strip().split()[-1].rstrip('w')
if ' ' in u else None}
for u in [f"http{p}" for p in s.split("http") if p]]
# Constants for checks
classes_to_check = frozenset(['button', 'icon', 'logo'])
tags_to_check = frozenset(['button', 'input'])
# Pre-fetch commonly used attributes
style = img.get('style', '')
alt = img.get('alt', '')
src = img.get('src', '')
data_src = img.get('data-src', '')
width = img.get('width')
height = img.get('height')
parent = img.parent
parent_classes = parent.get('class', [])
# Quick validation checks
if ('display:none' in style or
parent.name in tags_to_check or
any(c in cls for c in parent_classes for cls in classes_to_check) or
any(c in src for c in classes_to_check) or
any(c in alt for c in classes_to_check)):
return None
# Quick score calculation
score = 0
if width and width.isdigit():
width_val = int(width)
score += 1 if width_val > 150 else 0
if height and height.isdigit():
height_val = int(height)
score += 1 if height_val > 150 else 0
if alt:
score += 1
score += index/total_images < 0.5
image_format = ''
if "data:image/" in src:
image_format = src.split(',')[0].split(';')[0].split('/')[1].split(';')[0]
else:
image_format = os.path.splitext(src)[1].lower().strip('.').split('?')[0]
if image_format in ('jpg', 'png', 'webp', 'avif'):
score += 1
if score <= kwargs.get('image_score_threshold', IMAGE_SCORE_THRESHOLD):
return None
# Use set for deduplication
unique_urls = set()
image_variants = []
# Generate a unique group ID for this set of variants
group_id = index
# Base image info template
base_info = {
'alt': alt,
'desc': find_closest_parent_with_useful_text(img),
'score': score,
'type': 'image',
'group_id': group_id # Group ID for this set of variants
}
# Inline function for adding variants
def add_variant(src, width=None):
if src and not src.startswith('data:') and src not in unique_urls:
unique_urls.add(src)
image_variants.append({**base_info, 'src': src, 'width': width})
# Process all sources
add_variant(src)
add_variant(data_src)
# Handle srcset and data-srcset in one pass
for attr in ('srcset', 'data-srcset'):
if value := img.get(attr):
for source in parse_srcset(value):
add_variant(source['url'], source['width'])
# Quick picture element check
if picture := img.find_parent('picture'):
for source in picture.find_all('source'):
if srcset := source.get('srcset'):
for src in parse_srcset(srcset):
add_variant(src['url'], src['width'])
# Framework-specific attributes in one pass
for attr, value in img.attrs.items():
if attr.startswith('data-') and ('src' in attr or 'srcset' in attr) and 'http' in value:
add_variant(value)
return image_variants if image_variants else None
def remove_unwanted_attributes(element, important_attrs, keep_data_attributes=False):
attrs_to_remove = []
for attr in element.attrs:
if attr not in important_attrs:
if keep_data_attributes:
if not attr.startswith('data-'):
attrs_to_remove.append(attr)
else:
attrs_to_remove.append(attr)
for attr in attrs_to_remove:
del element[attr]
def process_element(element: element.PageElement) -> bool:
try:
if isinstance(element, NavigableString):
if isinstance(element, Comment):
element.extract()
return False
# if element.name == 'img':
# process_image(element, url, 0, 1)
# return True
if element.name in ['script', 'style', 'link', 'meta', 'noscript']:
element.decompose()
return False
keep_element = False
exclude_social_media_domains = SOCIAL_MEDIA_DOMAINS + kwargs.get('exclude_social_media_domains', [])
exclude_social_media_domains = list(set(exclude_social_media_domains))
try:
if element.name == 'a' and element.get('href'):
href = element.get('href', '').strip()
if not href: # Skip empty hrefs
return False
url_base = url.split('/')[2]
# Normalize the URL
try:
normalized_href = normalize_url(href, url)
except ValueError as e:
# logging.warning(f"Invalid URL format: {href}, Error: {str(e)}")
return False
link_data = {
'href': normalized_href,
'text': element.get_text().strip(),
'title': element.get('title', '').strip()
}
# Check for duplicates and add to appropriate dictionary
is_external = is_external_url(normalized_href, url_base)
if is_external:
if normalized_href not in external_links_dict:
external_links_dict[normalized_href] = link_data
else:
if normalized_href not in internal_links_dict:
internal_links_dict[normalized_href] = link_data
keep_element = True
# Handle external link exclusions
if is_external:
if kwargs.get('exclude_external_links', False):
element.decompose()
return False
elif kwargs.get('exclude_social_media_links', False):
if any(domain in normalized_href.lower() for domain in exclude_social_media_domains):
element.decompose()
return False
elif kwargs.get('exclude_domains', []):
if any(domain in normalized_href.lower() for domain in kwargs.get('exclude_domains', [])):
element.decompose()
return False
except Exception as e:
raise Exception(f"Error processing links: {str(e)}")
try:
if element.name == 'img':
potential_sources = ['src', 'data-src', 'srcset' 'data-lazy-src', 'data-original']
src = element.get('src', '')
while not src and potential_sources:
src = element.get(potential_sources.pop(0), '')
if not src:
element.decompose()
return False
# If it is srcset pick up the first image
if 'srcset' in element.attrs:
src = element.attrs['srcset'].split(',')[0].split(' ')[0]
# Check flag if we should remove external images
if kwargs.get('exclude_external_images', False):
src_url_base = src.split('/')[2]
url_base = url.split('/')[2]
if url_base not in src_url_base:
element.decompose()
return False
if not kwargs.get('exclude_external_images', False) and kwargs.get('exclude_social_media_links', False):
src_url_base = src.split('/')[2]
url_base = url.split('/')[2]
if any(domain in src for domain in exclude_social_media_domains):
element.decompose()
return False
# Handle exclude domains
if kwargs.get('exclude_domains', []):
if any(domain in src for domain in kwargs.get('exclude_domains', [])):
element.decompose()
return False
return True # Always keep image elements
except Exception as e:
raise "Error processing images"
# Check if flag to remove all forms is set
if kwargs.get('remove_forms', False) and element.name == 'form':
element.decompose()
return False
if element.name in ['video', 'audio']:
media[f"{element.name}s"].append({
'src': element.get('src'),
'alt': element.get('alt'),
'type': element.name,
'description': find_closest_parent_with_useful_text(element)
})
source_tags = element.find_all('source')
for source_tag in source_tags:
media[f"{element.name}s"].append({
'src': source_tag.get('src'),
'alt': element.get('alt'),
'type': element.name,
'description': find_closest_parent_with_useful_text(element)
})
return True # Always keep video and audio elements
if element.name in ONLY_TEXT_ELIGIBLE_TAGS:
if kwargs.get('only_text', False):
element.replace_with(element.get_text())
try:
remove_unwanted_attributes(element, IMPORTANT_ATTRS, kwargs.get('keep_data_attributes', False))
except Exception as e:
# print('Error removing unwanted attributes:', str(e))
self._log('error',
message="Error removing unwanted attributes: {error}",
tag="SCRAPE",
params={"error": str(e)}
)
# Process children
for child in list(element.children):
if isinstance(child, NavigableString) and not isinstance(child, Comment):
if len(child.strip()) > 0:
keep_element = True
else:
if process_element(child):
keep_element = True
# Check word count
if not keep_element:
word_count = len(element.get_text(strip=True).split())
keep_element = word_count >= word_count_threshold
if not keep_element:
element.decompose()
return keep_element
except Exception as e:
# print('Error processing element:', str(e))
self._log('error',
message="Error processing element: {error}",
tag="SCRAPE",
params={"error": str(e)}
)
return False
process_element(body)
# Update the links dictionary with unique links
links['internal'] = list(internal_links_dict.values())
links['external'] = list(external_links_dict.values())
# # Process images using ThreadPoolExecutor
imgs = body.find_all('img')
# For test we use for loop instead of thread
media['images'] = [
img for result in (process_image(img, url, i, len(imgs))
for i, img in enumerate(imgs))
if result is not None
for img in result
]
def flatten_nested_elements(node):
if isinstance(node, NavigableString):
return node
if len(node.contents) == 1 and isinstance(node.contents[0], element.Tag) and node.contents[0].name == node.name:
return flatten_nested_elements(node.contents[0])
node.contents = [flatten_nested_elements(child) for child in node.contents]
return node
body = flatten_nested_elements(body)
base64_pattern = re.compile(r'data:image/[^;]+;base64,([^"]+)')
for img in imgs:
src = img.get('src', '')
if base64_pattern.match(src):
# Replace base64 data with empty string
img['src'] = base64_pattern.sub('', src)
str_body = ""
try:
str_body = body.encode_contents().decode('utf-8')
except Exception as e:
# Reset body to the original HTML
success = False
body = BeautifulSoup(html, 'html.parser')
# Create a new div with a special ID
error_div = body.new_tag('div', id='crawl4ai_error_message')
error_div.string = '''
Crawl4AI Error: This page is not fully supported.
Possible reasons:
1. The page may have restrictions that prevent crawling.
2. The page might not be fully loaded.
Suggestions:
- Try calling the crawl function with these parameters:
magic=True,
- Set headless=False to visualize what's happening on the page.
If the issue persists, please check the page's structure and any potential anti-crawling measures.
'''
# Append the error div to the body
body.body.append(error_div)
str_body = body.encode_contents().decode('utf-8')
print(f"[LOG] 😧 Error: After processing the crawled HTML and removing irrelevant tags, nothing was left in the page. Check the markdown for further details.")
self._log('error',
message="After processing the crawled HTML and removing irrelevant tags, nothing was left in the page. Check the markdown for further details.",
tag="SCRAPE"
)
cleaned_html = str_body.replace('\n\n', '\n').replace(' ', ' ')
markdown_content = self._generate_markdown_content(
cleaned_html=cleaned_html,
html=html,
url=url,
success=success,
**kwargs
)
return {
**markdown_content,
'cleaned_html': cleaned_html,
'success': success,
'media': media,
'links': links,
'metadata': meta
}