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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_from(val):
 """Returns hex string representation for a given value. :param bytes|str|unicode|int|long val: :rtype: bytes|str """

    if isinstance(val, integer_types):
        hex_str = '%x' % val
        if len(hex_str) % 2:
            hex_str = '0' + hex_str
        return hex_str

    return hexlify(val)