Source code for langchain.utils.html
import re
from typing import List, Optional, Sequence, Union
from urllib.parse import urljoin, urlparse
PREFIXES_TO_IGNORE = ("javascript:", "mailto:", "#")
SUFFIXES_TO_IGNORE = (
    ".css",
    ".js",
    ".ico",
    ".png",
    ".jpg",
    ".jpeg",
    ".gif",
    ".svg",
    ".csv",
    ".bz2",
    ".zip",
    ".epub",
)
SUFFIXES_TO_IGNORE_REGEX = (
    "(?!" + "|".join([re.escape(s) + "[\#'\"]" for s in SUFFIXES_TO_IGNORE]) + ")"
)
PREFIXES_TO_IGNORE_REGEX = (
    "(?!" + "|".join([re.escape(s) for s in PREFIXES_TO_IGNORE]) + ")"
)
DEFAULT_LINK_REGEX = (
    f"href=[\"']{PREFIXES_TO_IGNORE_REGEX}((?:{SUFFIXES_TO_IGNORE_REGEX}.)*?)[\#'\"]"
)
[docs]def find_all_links(
    raw_html: str, *, pattern: Union[str, re.Pattern, None] = None
) -> List[str]:
    pattern = pattern or DEFAULT_LINK_REGEX
    return list(set(re.findall(pattern, raw_html)))
[docs]def extract_sub_links(
    raw_html: str,
    url: str,
    *,
    base_url: Optional[str] = None,
    pattern: Union[str, re.Pattern, None] = None,
    prevent_outside: bool = True,
    exclude_prefixes: Sequence[str] = (),
) -> List[str]:
    """Extract all links from a raw html string and convert into absolute paths.
    Args:
        raw_html: original html.