scrapeRL / backend /app /utils /html.py
NeerajCodz's picture
feat: add API routes and utility modules
27cde0c
raw
history blame
8.08 kB
"""HTML processing utilities for ScrapeRL backend."""
import re
from typing import Any, Optional
from bs4 import BeautifulSoup, Tag, NavigableString
from app.utils.logging import get_logger
logger = get_logger(__name__)
def parse_html(html: str, parser: str = "html.parser") -> BeautifulSoup:
"""
Parse HTML string into a BeautifulSoup object.
Args:
html: Raw HTML string
parser: Parser to use (html.parser, lxml, html5lib)
Returns:
Parsed BeautifulSoup object
"""
return BeautifulSoup(html, parser)
def clean_html(
html: str,
remove_scripts: bool = True,
remove_styles: bool = True,
remove_comments: bool = True,
remove_tags: Optional[list[str]] = None,
) -> str:
"""
Clean HTML by removing unwanted elements.
Args:
html: Raw HTML string
remove_scripts: Remove <script> tags
remove_styles: Remove <style> tags
remove_comments: Remove HTML comments
remove_tags: Additional tags to remove
Returns:
Cleaned HTML string
"""
soup = parse_html(html)
# Remove script tags
if remove_scripts:
for script in soup.find_all("script"):
script.decompose()
# Remove style tags
if remove_styles:
for style in soup.find_all("style"):
style.decompose()
# Remove comments
if remove_comments:
from bs4 import Comment
for comment in soup.find_all(string=lambda text: isinstance(text, Comment)):
comment.extract()
# Remove additional specified tags
if remove_tags:
for tag_name in remove_tags:
for tag in soup.find_all(tag_name):
tag.decompose()
return str(soup)
def extract_text(
html: str,
separator: str = " ",
strip: bool = True,
) -> str:
"""
Extract plain text from HTML.
Args:
html: Raw HTML string
separator: String to join text segments
strip: Strip whitespace from result
Returns:
Extracted plain text
"""
soup = parse_html(html)
# Remove script and style elements
for element in soup(["script", "style", "noscript"]):
element.decompose()
text = soup.get_text(separator=separator)
if strip:
# Normalize whitespace
text = re.sub(r"\s+", " ", text).strip()
return text
def semantic_chunk(
html: str,
max_chunk_size: int = 4000,
overlap: int = 200,
) -> list[dict[str, Any]]:
"""
Split HTML content into semantic chunks based on structure.
Args:
html: Raw HTML string
max_chunk_size: Maximum characters per chunk
overlap: Number of characters to overlap between chunks
Returns:
List of chunk dictionaries with text and metadata
"""
soup = parse_html(html)
chunks: list[dict[str, Any]] = []
# Remove non-content elements
for element in soup(["script", "style", "noscript", "nav", "footer", "header"]):
element.decompose()
# Find semantic boundaries
semantic_tags = ["article", "section", "div", "p", "h1", "h2", "h3", "h4", "h5", "h6"]
def get_text_content(element: Tag | NavigableString) -> str:
if isinstance(element, NavigableString):
return str(element).strip()
return element.get_text(separator=" ", strip=True)
current_chunk = ""
current_metadata: dict[str, Any] = {"tags": [], "headings": []}
for element in soup.find_all(semantic_tags):
text = get_text_content(element)
if not text:
continue
tag_name = element.name if isinstance(element, Tag) else "text"
# Check if adding this would exceed max size
if len(current_chunk) + len(text) + 1 > max_chunk_size:
if current_chunk:
chunks.append({
"text": current_chunk.strip(),
"metadata": current_metadata.copy(),
"char_count": len(current_chunk),
})
# Start new chunk with overlap
if overlap > 0 and current_chunk:
current_chunk = current_chunk[-overlap:] + " " + text
else:
current_chunk = text
current_metadata = {"tags": [tag_name], "headings": []}
else:
current_chunk += " " + text if current_chunk else text
current_metadata["tags"].append(tag_name)
# Track headings
if tag_name in ["h1", "h2", "h3", "h4", "h5", "h6"]:
current_metadata["headings"].append(text[:100])
# Add remaining content
if current_chunk.strip():
chunks.append({
"text": current_chunk.strip(),
"metadata": current_metadata,
"char_count": len(current_chunk),
})
# If no semantic chunks found, fall back to simple chunking
if not chunks:
text = extract_text(html)
for i in range(0, len(text), max_chunk_size - overlap):
chunk_text = text[i : i + max_chunk_size]
if chunk_text.strip():
chunks.append({
"text": chunk_text.strip(),
"metadata": {"tags": [], "headings": []},
"char_count": len(chunk_text),
})
return chunks
def extract_links(
html: str,
base_url: Optional[str] = None,
include_text: bool = True,
) -> list[dict[str, str]]:
"""
Extract all links from HTML.
Args:
html: Raw HTML string
base_url: Base URL for resolving relative links
include_text: Include link text in results
Returns:
List of link dictionaries with href and optionally text
"""
from urllib.parse import urljoin
soup = parse_html(html)
links: list[dict[str, str]] = []
for anchor in soup.find_all("a", href=True):
href = anchor.get("href", "")
if not href or href.startswith("#") or href.startswith("javascript:"):
continue
# Resolve relative URLs
if base_url and not href.startswith(("http://", "https://", "//")):
href = urljoin(base_url, href)
link_data: dict[str, str] = {"href": href}
if include_text:
link_data["text"] = anchor.get_text(strip=True)
# Include title if present
title = anchor.get("title")
if title:
link_data["title"] = title
links.append(link_data)
return links
def extract_tables(
html: str,
include_headers: bool = True,
) -> list[dict[str, Any]]:
"""
Extract tables from HTML as structured data.
Args:
html: Raw HTML string
include_headers: Try to identify and include header rows
Returns:
List of table dictionaries with headers and rows
"""
soup = parse_html(html)
tables: list[dict[str, Any]] = []
for table in soup.find_all("table"):
table_data: dict[str, Any] = {
"headers": [],
"rows": [],
}
# Extract headers from thead or first row
if include_headers:
thead = table.find("thead")
if thead:
header_row = thead.find("tr")
if header_row:
table_data["headers"] = [
th.get_text(strip=True)
for th in header_row.find_all(["th", "td"])
]
# Extract body rows
tbody = table.find("tbody") or table
for row in tbody.find_all("tr"):
cells = row.find_all(["td", "th"])
row_data = [cell.get_text(strip=True) for cell in cells]
# If no headers yet and this looks like a header row
if include_headers and not table_data["headers"] and row.find("th"):
table_data["headers"] = row_data
else:
if row_data: # Skip empty rows
table_data["rows"].append(row_data)
if table_data["rows"] or table_data["headers"]:
tables.append(table_data)
return tables