import itertools


def decode_years_to_min_max(summarized_year_string):
    """
    decode a summarized string of years into minimum & max. year values

    >>> decode_years_to_min_max('2000-2002, 2004')
    (2000, 2004)
    >>> decode_years_to_min_max('1992, 1994-1995')
    (1992, 1995)
    >>> decode_years_to_min_max('1750, 1752')
    (1750, 1752)
    >>> decode_years_to_min_max('1750-1751')
    (1750, 1751)
    >>> decode_years_to_min_max('1901')
    (1901, 1901)
    """
    tokens = []
    # split summary into groups of sequential digits or sequental non-digits
    for match, group_iterator in itertools.groupby(summarized_year_string
                                                   ,key=str.isdigit):
        group_string = ''.join(group_iterator)
        tokens.append(group_string)
    # pick off the first & last groups
    min_string = tokens[0]
    max_string = tokens[-1]
    return int(min_string), int(max_string)