Printable International Mobile Subscriber Identity (IMSI) numbers. Mind
    that there is no validation done on the actual correctness of the MCC/MNC.
    If you wish to validate IMSI numbers, take a look at `python-stdnum`_.

    :param number: string or int

    >>> print(imsi(2042312345))
    204-23-12345

    .. _python-stdnum: https://pypi.python.org/pypi/python-stdnum/

def imsi(number):
    '''
    Printable International Mobile Subscriber Identity (IMSI) numbers. Mind
    that there is no validation done on the actual correctness of the MCC/MNC.
    If you wish to validate IMSI numbers, take a look at `python-stdnum`_.

    :param number: string or int

    >>> print(imsi(2042312345))
    204-23-12345

    .. _python-stdnum: https://pypi.python.org/pypi/python-stdnum/
    '''
    number = to_decimal(number)
    groups = (number[:3], number[3:5], number[5:])
    return u'-'.join(list(filter(None, groups)))