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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 paddedInt(i):
    '''
    return a string that contains `i`, left-padded with 0's up to PAD_LEN digits
    '''
    i_str = str(i)
    pad = PAD_LEN - len(i_str)
    return (pad * "0") + i_str