试试这个

for col in categorical_features:
    if df.dtypes[col] == "object":
        print('object type')
    else:
        print(f'something else {df.dtypes[col]}')

你可以修改你的代码

categorical_features=df.columns.tolist()
for col in categorical_features:
    if df.dtypes[col] == "object"
       df[col]=encoder.fit_transform(df[col])

要选择Pandas中的所有对象类型列，可以用途：

categorical_features = df.select_dtypes(include=['object'])

select_dtypes()在Pandasv 0.14.1中发布