Source code for webtraversallibrary.selector

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This module contains heuristics for generating selectors.
from __future__ import annotations

import logging
from dataclasses import dataclass
from functools import total_ordering
from typing import Union

import bs4

logger = logging.getLogger("wtl")

[docs]@total_ordering @dataclass(frozen=True) class Selector: """ Web element selector based on CSS and XPATH. You may also specify an identifier (name or ID) of an iframe in which the given element is located. The class itself provides no guarantees on whether the selector is unique or even matches anything. The ``iframe`` value can be used if this selector refers to an element inside an iframe. Specify as ID or name. """ css: str = "*" xpath: str = "/" iframe: str = None def __lt__(self, other: Selector) -> bool: if len(self.css) == len(other.css): return self.xpath < other.xpath return len(self.css) < len(other.css)
[docs] @classmethod def build(cls, bs4_soup: bs4.BeautifulSoup, target: Union[bs4.Tag, int]) -> Selector: """ Compute xpath and css of a ``target`` in a bs4.BeautifulSoup. Will be verbose. Use a separate generalizer if you want reusable selectors. """ # Identify target if isinstance(target, bs4.Tag): element = target else: options = bs4_soup.find_all(attrs={"wtl-uid": target}) if len(options) != 1: logger.error("Invalid wtl-uid given to, returning blank selector") return cls(css="bad_wtl_uid_no_matches", xpath="bad_wtl_uid_no_matches") element = options[0] names, indices = [], [] child = element if else element.parent for parent in child.parents: siblings = parent.find_all(, recursive=False) index = 1 + siblings.index(child) names.append(cls._safe_tag_name( indices.append(-1 if len(siblings) == 1 else index) child = parent css_components = [ name if index == -1 else f"{name}:nth-of-type({index})" for (name, index) in zip(names, indices) ] xpath_components = [name if index == -1 else f"{name}[{index}]" for (name, index) in zip(names, indices)] css = ">".join(reversed(css_components)).strip() xpath = "/" + "/".join(reversed(xpath_components)).strip() return Selector(css=css, xpath=xpath)
@classmethod def _safe_tag_name(cls, name: str) -> str: if ":" in name or "=" in name: return "*" return name