import re


def _parse_abbreviation(uri_link):
    """
    Returns a team's abbreviation.

    A school or team's abbreviation is generally embedded in a URI link which
    contains other relative link information. For example, the URI for the
    New England Patriots for the 2017 season is "/teams/nwe/2017.htm". This
    function strips all of the contents before and after "nwe" and converts it
    to uppercase and returns "NWE".

    Parameters
    ----------
    uri_link : string
        A URI link which contains a team's abbreviation within other link
        contents.

    Returns
    -------
    string
        The shortened uppercase abbreviation for a given team.
    """
    abbr = re.sub(r'/[0-9]+\..*htm.*', '', uri_link('a').attr('href'))
    abbr = re.sub(r'/.*/schools/', '', abbr)
    abbr = re.sub(r'/teams/', '', abbr)
    return abbr.upper()