从pandas数据帧中删除停止字

import pandas as pd

df = pd.DataFrame({'文本': ['Hello world!', 'Stop word removal', 'This is a test']})

stop_words = ['stop', 'is', 'a']

df['文本'] = df['文本'].apply(lambda x: ' '.join([word for word in x.split() if word.lower() not in stop_words]))