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1# This file is dual licensed under the terms of the Apache License, Version2# 2.0, and the BSD License. See the LICENSE file in the root of this repository3# for complete details.4 5from typing import Any, Iterator, Optional, Set6 7from ._parser import parse_requirement as _parse_requirement8from ._tokenizer import ParserSyntaxError9from .markers import Marker, _normalize_extra_values10from .specifiers import SpecifierSet11from .utils import canonicalize_name12 13 14class InvalidRequirement(ValueError):15    """16    An invalid requirement was found, users should refer to PEP 508.17    """18 19 20class Requirement:21    """Parse a requirement.22 23    Parse a given requirement string into its parts, such as name, specifier,24    URL, and extras. Raises InvalidRequirement on a badly-formed requirement25    string.26    """27 28    # TODO: Can we test whether something is contained within a requirement?29    #       If so how do we do that? Do we need to test against the _name_ of30    #       the thing as well as the version? What about the markers?31    # TODO: Can we normalize the name and extra name?32 33    def __init__(self, requirement_string: str) -> None:34        try:35            parsed = _parse_requirement(requirement_string)36        except ParserSyntaxError as e:37            raise InvalidRequirement(str(e)) from e38 39        self.name: str = parsed.name40        self.url: Optional[str] = parsed.url or None41        self.extras: Set[str] = set(parsed.extras if parsed.extras else [])42        self.specifier: SpecifierSet = SpecifierSet(parsed.specifier)43        self.marker: Optional[Marker] = None44        if parsed.marker is not None:45            self.marker = Marker.__new__(Marker)46            self.marker._markers = _normalize_extra_values(parsed.marker)47 48    def _iter_parts(self, name: str) -> Iterator[str]:49        yield name50 51        if self.extras:52            formatted_extras = ",".join(sorted(self.extras))53            yield f"[{formatted_extras}]"54 55        if self.specifier:56            yield str(self.specifier)57 58        if self.url:59            yield f"@ {self.url}"60            if self.marker:61                yield " "62 63        if self.marker:64            yield f"; {self.marker}"65 66    def __str__(self) -> str:67        return "".join(self._iter_parts(self.name))68 69    def __repr__(self) -> str:70        return f"<Requirement('{self}')>"71 72    def __hash__(self) -> int:73        return hash(74            (75                self.__class__.__name__,76                *self._iter_parts(canonicalize_name(self.name)),77            )78        )79 80    def __eq__(self, other: Any) -> bool:81        if not isinstance(other, Requirement):82            return NotImplemented83 84        return (85            canonicalize_name(self.name) == canonicalize_name(other.name)86            and self.extras == other.extras87            and self.specifier == other.specifier88            and self.url == other.url89            and self.marker == other.marker90        )91