import ast, os
n=0
libdir = 'C:/programs/Python34/Lib'
for root, dirs, files in os.walk(libdir):
    print(root)
    if root.endswith('site-packages'):
        dirs.clear()
        continue
    os.chdir(root)
    for fname in files:
        if fname.endswith('.py'):
            with open(fname, encoding='utf-8') as f:
                try:
                    tree = ast.parse(f.read())
                except (UnicodeDecodeError, SyntaxError):
                    continue
                try:
                    compile(tree, fname, 'exec')
                    n += 1
                except Exception as e:
                    if not fname.startswith('badsyntax'):
                        print(root, fname, type(e).__name__, e)
print(n)