You will need to os.path.join the path you invoke listdir on with the found file/directory, i.e.
for each in os.listdir(path):
if os.path.isdir(os.path.join(path, each)):
....
If you don't create an absolute path this way you will be testing against your current working directory in stead, which probably dioesn't have the svn directory.
Also, don't explicitly compare boolean values. Let if handle it as a boolean expression (some functions may return non True/False truth values, i.e. None or an instance)