def keywords_by_branch(branch, df):
    """
    gets list of keywords within a specified federal branch
    
    params:
    
    df to search
    branch to filter by
    
    """
    soldf = df

    branch_df = soldf[soldf['Branch'] == f'{branch}']

    branch_words = [words for words in branch_df['Keywords']]

    branch_all = []
    for words in branch_words:
        branch_all.extend(words)

    return branch_all