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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 change_base(x: int, base: int):
    """Change numerical base of input number x to base. return string representation after the conversion. base numbers are less than 10. '22' '1000' '111' """
    ret = ""
    while x > 0:
        ret = str(x % base) + ret
        x //= base
    return ret
