feat(extraction): add RegexExtractionStrategy for pattern-based extraction

Add new RegexExtractionStrategy for fast, zero-LLM extraction of common data types:
- Built-in patterns for emails, URLs, phones, dates, and more
- Support for custom regex patterns
- LLM-assisted pattern generation utility
- Optimized HTML preprocessing with fit_html field
- Enhanced network response body capture

Breaking changes: None
This commit is contained in:
UncleCode
2025-05-02 21:15:24 +08:00
parent 94e9959fe0
commit 9b5ccac76e
13 changed files with 984 additions and 124 deletions

View File

@@ -3,42 +3,19 @@ from crawl4ai import (
AsyncWebCrawler,
BrowserConfig,
CrawlerRunConfig,
CacheMode,
DefaultMarkdownGenerator,
PruningContentFilter,
CrawlResult
)
async def example_cdp():
browser_conf = BrowserConfig(
headless=False,
cdp_url="http://localhost:9223"
)
crawler_config = CrawlerRunConfig(
session_id="test",
js_code = """(() => { return {"result": "Hello World!"} })()""",
js_only=True
)
async with AsyncWebCrawler(
config=browser_conf,
verbose=True,
) as crawler:
result : CrawlResult = await crawler.arun(
url="https://www.helloworld.org",
config=crawler_config,
)
print(result.js_execution_result)
async def main():
browser_config = BrowserConfig(headless=False, verbose=True)
async def main():
browser_config = BrowserConfig(headless=True, verbose=True)
async with AsyncWebCrawler(config=browser_config) as crawler:
crawler_config = CrawlerRunConfig(
cache_mode=CacheMode.BYPASS,
markdown_generator=DefaultMarkdownGenerator(
content_filter=PruningContentFilter(
threshold=0.48, threshold_type="fixed", min_word_threshold=0
)
content_filter=PruningContentFilter()
),
)
result : CrawlResult = await crawler.arun(

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@@ -0,0 +1,143 @@
# == File: regex_extraction_quickstart.py ==
"""
Miniquick-start for RegexExtractionStrategy
────────────────────────────────────────────
3 bite-sized demos that parallel the style of *quickstart_examples_set_1.py*:
1. **Default catalog** scrape a page and pull out e-mails / phones / URLs, etc.
2. **Custom pattern** add your own regex at instantiation time.
3. **LLM-assisted schema** ask the model to write a pattern, cache it, then
run extraction _without_ further LLM calls.
Run the whole thing with::
python regex_extraction_quickstart.py
"""
import os, json, asyncio
from pathlib import Path
from typing import List
from crawl4ai import (
AsyncWebCrawler,
CrawlerRunConfig,
CrawlResult,
RegexExtractionStrategy,
LLMConfig,
)
# ────────────────────────────────────────────────────────────────────────────
# 1. Default-catalog extraction
# ────────────────────────────────────────────────────────────────────────────
async def demo_regex_default() -> None:
print("\n=== 1. Regex extraction default patterns ===")
url = "https://www.iana.org/domains/example" # has e-mail + URLs
strategy = RegexExtractionStrategy(
pattern = RegexExtractionStrategy.Url | RegexExtractionStrategy.Currency
)
config = CrawlerRunConfig(extraction_strategy=strategy)
async with AsyncWebCrawler() as crawler:
result: CrawlResult = await crawler.arun(url, config=config)
print(f"Fetched {url} - success={result.success}")
if result.success:
data = json.loads(result.extracted_content)
for d in data[:10]:
print(f" {d['label']:<12} {d['value']}")
print(f"... total matches: {len(data)}")
else:
print(" !!! crawl failed")
# ────────────────────────────────────────────────────────────────────────────
# 2. Custom pattern override / extension
# ────────────────────────────────────────────────────────────────────────────
async def demo_regex_custom() -> None:
print("\n=== 2. Regex extraction custom price pattern ===")
url = "https://www.apple.com/shop/buy-mac/macbook-pro"
price_pattern = {"usd_price": r"\$\s?\d{1,3}(?:,\d{3})*(?:\.\d{2})?"}
strategy = RegexExtractionStrategy(custom = price_pattern)
config = CrawlerRunConfig(extraction_strategy=strategy)
async with AsyncWebCrawler() as crawler:
result: CrawlResult = await crawler.arun(url, config=config)
if result.success:
data = json.loads(result.extracted_content)
for d in data:
print(f" {d['value']}")
if not data:
print(" (No prices found - page layout may have changed)")
else:
print(" !!! crawl failed")
# ────────────────────────────────────────────────────────────────────────────
# 3. One-shot LLM pattern generation, then fast extraction
# ────────────────────────────────────────────────────────────────────────────
async def demo_regex_generate_pattern() -> None:
print("\n=== 3. generate_pattern → regex extraction ===")
cache_dir = Path(__file__).parent / "tmp"
cache_dir.mkdir(exist_ok=True)
pattern_file = cache_dir / "price_pattern.json"
url = "https://www.lazada.sg/tag/smartphone/"
# ── 3-A. build or load the cached pattern
if pattern_file.exists():
pattern = json.load(pattern_file.open(encoding="utf-8"))
print("Loaded cached pattern:", pattern)
else:
print("Generating pattern via LLM…")
llm_cfg = LLMConfig(
provider="openai/gpt-4o-mini",
api_token="env:OPENAI_API_KEY",
)
# pull one sample page as HTML context
async with AsyncWebCrawler() as crawler:
html = (await crawler.arun(url)).fit_html
pattern = RegexExtractionStrategy.generate_pattern(
label="price",
html=html,
query="Prices in Malaysian Ringgit (e.g. RM1,299.00 or RM200)",
llm_config=llm_cfg,
)
json.dump(pattern, pattern_file.open("w", encoding="utf-8"), indent=2)
print("Saved pattern:", pattern_file)
# ── 3-B. extraction pass zero LLM calls
strategy = RegexExtractionStrategy(custom=pattern)
config = CrawlerRunConfig(extraction_strategy=strategy, delay_before_return_html=3)
async with AsyncWebCrawler() as crawler:
result: CrawlResult = await crawler.arun(url, config=config)
if result.success:
data = json.loads(result.extracted_content)
for d in data[:15]:
print(f" {d['value']}")
print(f"... total matches: {len(data)}")
else:
print(" !!! crawl failed")
# ────────────────────────────────────────────────────────────────────────────
# Entrypoint
# ────────────────────────────────────────────────────────────────────────────
async def main() -> None:
# await demo_regex_default()
# await demo_regex_custom()
await demo_regex_generate_pattern()
if __name__ == "__main__":
asyncio.run(main())