Simplify with built-in functions where possible. e.g.

change [x for x in y if x] to filter(None, y)
change [f(x) for x in y] to map(f, x)
change [x for x in y] to list(y)

These changes reduce source code size and complexity and produce some minor performance gains

svn: r14104

src/gen/proxy/private.py

@@ -377,7 +377,7 @@ class PrivateProxyDb(ProxyDbBase):
         Note that this is a generator function, it returns a iterator for
         use in loops. If you want a list of the results use:
 
-        >    result_list = [i for i in find_backlink_handles(handle)]
+        >    result_list = list(find_backlink_handles(handle))
         """
         
         # This isn't done yet because it doesn't check if references are