Pulled find_package functionality into a PackageFinder class

setuptools/__init__.py

@@ -29,7 +29,10 @@ run_2to3_on_doctests = True
 # Standard package names for fixer packages
 lib2to3_fixer_packages = ['lib2to3.fixes']
 
-def find_packages(where='.', exclude=(), include=('*',)):
+
+class PackageFinder(object):
+    @classmethod
+    def find(cls, where='.', exclude=(), include=('*',)):
         """Return a list all Python packages found within directory 'where'
 
         'where' should be supplied as a "cross-platform" (i.e. URL-style) path; it
@@ -46,14 +49,15 @@ def find_packages(where='.', exclude=(), include=('*',)):
         The list of included packages is built up first and then any explicitly
         excluded packages are removed from it.
         """
-    out = _find_packages_iter(convert_path(where))
-    includes = _build_filter(*include)
-    excludes = _build_filter('ez_setup', '*__pycache__', *exclude)
+        out = cls._find_packages_iter(convert_path(where))
+        includes = cls._build_filter(*include)
+        excludes = cls._build_filter('ez_setup', '*__pycache__', *exclude)
         out = filter(includes, out)
         out = filterfalse(excludes, out)
         return list(out)
 
-def _all_dirs(base_path):
+    @staticmethod
+    def _all_dirs(base_path):
         """
         Return all dirs in base_path, relative to base_path
         """
@@ -61,30 +65,35 @@ def _all_dirs(base_path):
             for dir in dirs:
                 yield os.path.relpath(os.path.join(root, dir), base_path)
 
-def _find_packages_iter(base_path):
-    dirs = _all_dirs(base_path)
+    @classmethod
+    def _find_packages_iter(cls, base_path):
+        dirs = cls._all_dirs(base_path)
         suitable = filterfalse(lambda n: '.' in n, dirs)
         packages = (
             path
             for path in suitable
-        if _looks_like_package(os.path.join(base_path, path))
+            if cls._looks_like_package(os.path.join(base_path, path))
         )
         for pkg_path in packages:
             yield pkg_path.replace(os.path.sep, '.')
 
-def _looks_like_package(path):
+    @staticmethod
+    def _looks_like_package(path):
         return (
             os.path.isfile(os.path.join(path, '__init__.py'))
             or sys.version_info[:2] >= (3, 3)  # PEP 420
         )
 
-def _build_filter(*patterns):
+    @staticmethod
+    def _build_filter(*patterns):
         """
         Given a list of patterns, return a callable that will be true only if
         the input matches one of the patterns.
         """
         return lambda name: any(fnmatchcase(name, pat=pat) for pat in patterns)
 
+find_packages = PackageFinder.find
+
 setup = distutils.core.setup
 
 _Command = _get_unpatched(_Command)