initial commit

Lib/site-packages/pip/_internal/distributions/installed.py

@@ -0,0 +1,29 @@
+from typing import Optional
+
+from pip._internal.distributions.base import AbstractDistribution
+from pip._internal.index.package_finder import PackageFinder
+from pip._internal.metadata import BaseDistribution
+
+
+class InstalledDistribution(AbstractDistribution):
+    """Represents an installed package.
+
+    This does not need any preparation as the required information has already
+    been computed.
+    """
+
+    @property
+    def build_tracker_id(self) -> Optional[str]:
+        return None
+
+    def get_metadata_distribution(self) -> BaseDistribution:
+        assert self.req.satisfied_by is not None, "not actually installed"
+        return self.req.satisfied_by
+
+    def prepare_distribution_metadata(
+        self,
+        finder: PackageFinder,
+        build_isolation: bool,
+        check_build_deps: bool,
+    ) -> None:
+        pass