Воркед

venv/Lib/site-packages/pip/_internal/resolution/resolvelib/base.py

@@ -1,31 +1,29 @@
-from typing import FrozenSet, Iterable, Optional, Tuple, Union
+from dataclasses import dataclass
+from typing import FrozenSet, Iterable, Optional, Tuple
 
 from pip._vendor.packaging.specifiers import SpecifierSet
-from pip._vendor.packaging.utils import NormalizedName, canonicalize_name
-from pip._vendor.packaging.version import LegacyVersion, Version
+from pip._vendor.packaging.utils import NormalizedName
+from pip._vendor.packaging.version import Version
 
 from pip._internal.models.link import Link, links_equivalent
 from pip._internal.req.req_install import InstallRequirement
 from pip._internal.utils.hashes import Hashes
 
 CandidateLookup = Tuple[Optional["Candidate"], Optional[InstallRequirement]]
-CandidateVersion = Union[LegacyVersion, Version]
 
 
-def format_name(project: str, extras: FrozenSet[str]) -> str:
+def format_name(project: NormalizedName, extras: FrozenSet[NormalizedName]) -> str:
     if not extras:
         return project
-    canonical_extras = sorted(canonicalize_name(e) for e in extras)
-    return "{}[{}]".format(project, ",".join(canonical_extras))
+    extras_expr = ",".join(sorted(extras))
+    return f"{project}[{extras_expr}]"
 
 
+@dataclass(frozen=True)
 class Constraint:
-    def __init__(
-        self, specifier: SpecifierSet, hashes: Hashes, links: FrozenSet[Link]
-    ) -> None:
-        self.specifier = specifier
-        self.hashes = hashes
-        self.links = links
+    specifier: SpecifierSet
+    hashes: Hashes
+    links: FrozenSet[Link]
 
     @classmethod
     def empty(cls) -> "Constraint":
@@ -116,7 +114,7 @@ class Candidate:
         raise NotImplementedError("Override in subclass")
 
     @property
-    def version(self) -> CandidateVersion:
+    def version(self) -> Version:
         raise NotImplementedError("Override in subclass")
 
     @property