initial import of the packaging package in the standard library

Lib/packaging/pypi/base.py

@@ -0,0 +1,48 @@
+"""Base class for index crawlers."""
+
+from packaging.pypi.dist import ReleasesList
+
+
+class BaseClient:
+    """Base class containing common methods for the index crawlers/clients"""
+
+    def __init__(self, prefer_final, prefer_source):
+        self._prefer_final = prefer_final
+        self._prefer_source = prefer_source
+        self._index = self
+
+    def _get_prefer_final(self, prefer_final=None):
+        """Return the prefer_final internal parameter or the specified one if
+        provided"""
+        if prefer_final:
+            return prefer_final
+        else:
+            return self._prefer_final
+
+    def _get_prefer_source(self, prefer_source=None):
+        """Return the prefer_source internal parameter or the specified one if
+        provided"""
+        if prefer_source:
+            return prefer_source
+        else:
+            return self._prefer_source
+
+    def _get_project(self, project_name):
+        """Return an project instance, create it if necessary"""
+        return self._projects.setdefault(project_name.lower(),
+                    ReleasesList(project_name, index=self._index))
+
+    def download_distribution(self, requirements, temp_path=None,
+                              prefer_source=None, prefer_final=None):
+        """Download a distribution from the last release according to the
+        requirements.
+
+        If temp_path is provided, download to this path, otherwise, create a
+        temporary location for the download and return it.
+        """
+        prefer_final = self._get_prefer_final(prefer_final)
+        prefer_source = self._get_prefer_source(prefer_source)
+        release = self.get_release(requirements, prefer_final)
+        if release:
+            dist = release.get_distribution(prefer_source=prefer_source)
+            return dist.download(temp_path)