你可以只遍历要替换的单词，而不是每行一个单词。注意regex参数，它允许查找和替换子字符串。你可以在pandas.DataFrame.replacehere的文档中找到更多信息。

import pandas as pd

word = ['dog', 'cat', 'fish']

dfa = pd.DataFrame({'a': ['big dog', 'good food', 'dog and cat', 'little fish', 'intense light', 'nice cat']})

for w in word:
    dfa = dfa.replace(w, "animal", regex=True)

print(dfa)

此输出

a
0         big animal
1          good food
2  animal and animal
3      little animal
4      intense light
5        nice animal

import pandas as pd

dfa = pd.DataFrame({'a': ['big dog', 'good food', 'dog and cat', 'little fish', 'intense light', 'nice cat']})
word = ['dog', 'cat', 'fish']

out = dfa["a"].str.replace(f"({'|'.join(word)})", "animal", regex=True)

0           big animal
1            good food
2    animal and animal
3        little animal
4        intense light
5          nice animal
Name: a, dtype: object

用途

dfa['a'] = dfa['a'].str.replace(w, "animal")