将 dataframe 的列从 0 重命名为字符串（重命名无效）

Question

I have a dataframe that looks like the following

	index	0	feature2	feature3
0	zipcode	0.10	y	z
1	latitude	0.56	y	z
2	longitude	0.39	y	z

I have used the following code to change the 0, the third column name to something else, but when I output the dataframe again nothing has changed and the column is still 0.

df.rename(index = {0: 'feature_rank'})
# Or alternatively
df.rename(column = {0: 'feature_rank'})

I would also like to know if it is possible to change the name of the second column to something else. Once again rename is not working for the 'index' column

Answer 1

DataFrame.rename() returns you a new dataframe with the columns renamed (this is usefull when doing method-chaining).

You want to keep the result by doing:

df = df.rename(column={0: 'feature_rank'})

Alternatively it has an argument (called inplace ) that allows you to do the operation in place (so you wouldn't need to re-assign):

df.rename(column={0: 'feature_rank'}, inplace=True)

If you want to rename multiple columns you can just add them to the dictionary, eg:

df = df.rename(column={0: 'feature_rank', 'feature2': 'my_new_name_for_feature2'})

Note

About using df.rename(index=...) vs. df.rename(columns=...) those would have different results. Setting the index parameter would rename the rows, setting the columns parameter would instead rename the columns.

Eg:

df = df.rename(column={0: 'feature_rank'})

	index	feature_rank	feature2	feature3
0	zipcode	0.10	y	z
1	latitude	0.56	y	z
2	longitude	0.39	y	z

Instead:

df = df.rename(index={0: 'feature_rank'})

	index	0	feature2	feature3
feature_rank	zipcode	0.10	y	z
1	latitude	0.56	y	z
2	longitude	0.39	y	z

Answer 2

Hope this will work.

df.rename(columns = {'0':'feature_rank'}, inplace = True)

Answer 3

You should try this:

df.rename(column={'0':'feature_rank', 'feature2': 'my_new_name_for_feature2'}, inplace=True)