Normalize distribution name with pkg_resources

`pypa/installer` is used to parse Wheel metadata, but does not currently
provide a method for normalizing distribution names:

- pypa/installer#97

`pypa/pkg_resources` provides `Requirement.parse` which returns an instance
of `Requirement` where `.key` is the canonical distribution name per PEP 503.

The `Requirement` class can also parse `extras`, but it returns a normalized
form that I believe could break the installation of the extras.

python/pip_install/extract_wheels/lib/bazel.py

@@ -10,7 +10,6 @@
     annotation,
     namespace_pkgs,
     purelib,
-    requirements,
     wheel,
 )
 
@@ -384,7 +383,7 @@ def extract_wheel(
     if not enable_implicit_namespace_pkgs:
         setup_namespace_pkg_compatibility(directory)
 
-    extras_requested = extras.get(requirements.sanitise_requirement(whl.name), set())
+    extras_requested = extras[whl.name] if whl.name in extras else set()
     whl_deps = sorted(whl.dependencies(extras_requested))
 
     if incremental:

python/pip_install/extract_wheels/lib/requirements.py

@@ -1,6 +1,8 @@
 import re
 from typing import Dict, Optional, Set, Tuple
 
+import pkg_resources
+
 
 def parse_extras(requirements_path: str) -> Dict[str, Set[str]]:
     """Parse over the requirements.txt file to find extras requested.
@@ -23,13 +25,6 @@ def parse_extras(requirements_path: str) -> Dict[str, Set[str]]:
     return extras_requested
 
 
-def sanitise_requirement(requirement: str) -> str:
-    """Given a requirement string, returns a normalized version of the requirement name.
-    https://peps.python.org/pep-0503/#normalized-names
-    """
-    return re.sub(r"[-_.]+", "-", requirement).lower()
-
-
 def _parse_requirement_for_extra(
     requirement: str,
 ) -> Tuple[Optional[str], Optional[Set[str]]]:
@@ -45,7 +40,7 @@ def _parse_requirement_for_extra(
     matches = extras_pattern.match(requirement)
     if matches:
         return (
-            sanitise_requirement(matches.group(1)),
+            pkg_resources.Requirement.parse(matches.group(1)).key,
             {extra.strip() for extra in matches.group(2).split(",")},
         )
 

python/pip_install/extract_wheels/lib/wheel.py

@@ -38,7 +38,8 @@ def path(self) -> str:
     @property
     def name(self) -> str:
         # TODO Also available as installer.sources.WheelSource.distribution
-        return str(self.metadata['Name'])
+        name = str(self.metadata['Name'])
+        return pkg_resources.Requirement.parse(name).key
 
     @property
     def metadata(self) -> email.message.Message: