Actually, I think I'm wrong about python's behavior, at least now; it doesn't omit the files, and instead does something with surrogates. On Linux:

    >>> b'\xc0'.decode('utf-8')
    Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
    UnicodeDecodeError: 'utf-8' codec can't decode byte 0xc0 in position 0: invalid start byte
    >>> open(b'\xc0', 'w').write('foo')
    3
    >>> os.listdir()
    ['\udcc0']
    >>> open(b'\xc0').read()
    'foo'
    >>> open('\udcc0').read()
    'foo'