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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def hex_to_bytes(s):
 """ convert hex string to bytes """

    if len(s) % 2:
        s = b'0' + s
    ia = [int(s[i:i+2], 16) for i in range(0, len(s), 2)]   # int array
    return bs(ia) if PYTHON_MAJOR_VER == 3 else b''.join([chr(c) for c in ia])