def _numbers_units ( N ) : lst = range ( 1 , N + 1 ) return "" . join ( list ( map ( lambda i : str ( i % 10 ) , lst ) ) )
how to make a string of numbers n python
>>> _numbers_units ( 45 ) 123456789012345678901234567890123456789012345
def _numbers_units(N):
    """
    >>> _numbers_units(45)
    '123456789012345678901234567890123456789012345'
    """
    lst = range(1, N + 1)
    return "".join(list(map(lambda i: str(i % 10), lst)))