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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 record_diff(old, new):
 """ Generate a human-readable diff of two performance records. """

    return '\n'.join(difflib.ndiff(
        ['%s: %s' % (k, v) for op in old for k, v in op.items()],
        ['%s: %s' % (k, v) for op in new for k, v in op.items()],
    ))