def split_apt(field):
    """
    Parses the ADDRESS field (<site address>, <apt number> <municipality>) from the CLEMIS CFS Report
    and returns the apartment number.
    """

    if ',' in field:
        f = field.split(', ')
        f = f[1]
        f = f.split(' ')
        apt = f[0]
    else:
        apt = None
    return apt