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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 dict2cols(d, spaces=2, separator=' '):
 """ Take a dict of string keys and string values, and return a string with them formatted as two columns separated by at least ``spaces`` number of ``separator`` characters. :param d: dict of string keys, string values :type d: dict :param spaces: number of spaces to separate columns by :type spaces: int :param separator: character to fill in between columns :type separator: str """

    if len(d) == 0:
        return ''
    s = ''
    maxlen = max([len(k) for k in d.keys()])
    fmt_str = '{k:' + separator + '<' + str(maxlen + spaces) + '}{v}\n'
    for k in sorted(d.keys()):
        s += fmt_str.format(
            k=k,
            v=d[k],
        )
    return s