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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 pretty_print(n):
 """Pretty print function for very big integers"""

    if type(n) != int:
        return n

    ret = []
    n = str(n)
    for i in range(len(n) - 1, -1, -1):
        ret.append(n[i])
        if (len(n) - i) % 3 == 0:
            ret.append(',')
    ret.reverse()
    return ''.join(ret[1:]) if ret[0] == ',' else ''.join(ret)