>>> import os

>>> def enumfiles(path, dest):

	files = os.listdir(path)

	for f in files:

		subpath = path + '/' + f

		if (os.path.isfile(subpath)):

			dest.append(subpath)

		elif (os.path.isdir(subpath)):

			if (f[0] == '.'):

				pass

			else:

				enumfiles(subpath, dest)

>>> files = []

>>> path = "D:\cocos2d-x-2.2.3"

>>> enumfiles(path, files)

>>> exts = {}

>>> for f in files:

	l = len(f)

	p = f.rfind('.')

	s = f.rfind('/')

	if (l>0 and p!=-1 and p>s):

		ext = f[p:l]

		exts[ext] = 0

>>> exts.keys()