While working on one project I've met a problem that I can't to specify to not tuch my configuration files for python package that uses setup.py technique. To solve this problem I've implemented the following solution that works for me. If this idea worths it, I could made a pacth relative needed version of python.

+class smart_install_data(install_data):
+    def run(self):
+        # Use revers order for safe removal
+        for i in range(len(self.data_files)-1, -1, -1):
+            f = self.data_files[i]
+            if type(f) is StringType:
+                continue
+            if len(f) <= 2:
+               continue
+            # Ok, we have additional value, do some magick according it.
+            if f[2] != "preserve":
+                # Nope, we do not know it. Just ignore for now.
+                # Should we scream about it?
+                continue
+            # Check a tuple with path to install to and a list of files
+            dir = convert_path(f[0])
+            if not os.path.isabs(dir):
+                dir = os.path.join(self.install_dir, dir)
+            elif self.root:
+                dir = change_root(self.root, dir)
+
+            if f[1] == []:
+                # If there are no files listed, the user must be
+                # trying to create an empty directory, so just ignore
+                # it.
+                # Should we scream in this case?
+                continue
+
+            # Check files one by one.
+            # Use revers order for safe removal
+            for j in range(len(f[1])-1, -1, -1):
+                data=f[1][j]
+                data = convert_path(data)
+                if not os.path.isfile(data):
+                    # Again skip dirs.
+                    continue
+                dst = os.path.join(dir, os.path.basename(data))
+                if not os.path.exists(dst):
+                    continue
+                del f[1][j]
+            if len(f[1]) == 0:
+                del self.data_files[i]
+
+        return install_data.run(self)

 setup(name = 'usher',
       version = '0.1',
       package_dir = { 'usher':'python' },
       packages = ['usher', 'usher.ushercli', 'usher.usherlnm', 'usher.utils', 'usher.usherctrl'],
+      cmdclass = {'install_data':smart_install_data},
       data_files = [
           ('/etc/init.d', ['initscripts/usherctrl', 'initscripts/usherlnm']),
-          ('/etc/usher', ['configs/usherctrl.config', 'configs/usherlnm.config', 'configs/ushercli.config']),
+          ('/etc/usher', ['configs/usherctrl.config', 'configs/usherlnm.config', 'configs/ushercli.config'], "preserve"),
           ("/usr/lib/python%s/site-packages/usher/usherctrl" % pyver, ['python/usherctrl/app.tac']),
           ("/usr/lib/python%s/site-packages/usher/usherlnm" % pyver, ['python/usherlnm/app.tac'])
       ]

Please suggest this feature to the distutils-sig first (http://www.python.org/community/sigs/current/distutils-sig/)

After collecting feedback, please resubmit it as a new patch, and use a file attachment then, rather than including it in the message itself (it is incomprehensible as it stands). Also please include documentation changes.