def lowercase_team_names(df_orig):
    """
    Accepts a Dataframe with columns h and a
    representing home and away team names with strings
    makes these team names lowercase, replaces spaces with dashes,
    and strips out dots
    Returns the amended dataframe
    """
    df = df_orig.copy(deep=True)
    for col in ['h', 'a']:
        df[col] = df[col].str.lower().str.replace(' ', '-').\
            str.replace('.', '')
    return df