How to add suffix to column names except some columns?

Question

Given pandas DataFrame, how can I add the suffix “_old” to all columns except two columns Id and Name?

import pandas as pd
data = [[1,'Alex',22,'single'],[2,'Bob',32,'married'],[3,'Clarke',23,'single']]
df = pd.DataFrame(data,columns=['Id','Name','Age','Status'])

Asked By: ScalaBoy

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Source

Answer 1

Using map

df.columns=df.columns.map(lambda x : x+'_old' if x !='Id' and x!='Name' else x)
df
Out[181]: 
   Id    Name  Age_old Status_old
0   1    Alex       22     single
1   2     Bob       32    married
2   3  Clarke       23     single

Answered By: BENY

Answer 2

You can reassign the dataframe’s columns:

>>> df
   Id    Name  Age   Status
0   1    Alex   22   single
1   2     Bob   32  married
2   3  Clarke   23   single
>>> 
>>> keep_same = {'Id', 'Name'}
>>> df.columns = ['{}{}'.format(c, '' if c in keep_same else '_old')
...:               for c in df.columns]
>>>
>>> df
   Id    Name  Age_old Status_old
0   1    Alex       22     single
1   2     Bob       32    married
2   3  Clarke       23     single

Answered By: timgeb

Answer 3

You can use the rename method which takes a dictionary of {column -> new_name}:

df.rename(columns={c: c+'_old' for c in df.columns if c not in ['Id', 'Name']})

Answered By: Max Segal

Answer 4

Now, you can do this in pandas with df.add_suffix()

https://pandas.pydata.org/pandas-docs/stable/reference/api/pandas.DataFrame.add_suffix.html

Answered By: Anna DW

Answer 5

df.rename(columns = lambda col: f"{col}_old" 
                                if col not in ('Name', 'Id') 
                                else col
          )

   Id    Name  Age_old Status_old
0   1    Alex       22     single
1   2     Bob       32    married
2   3  Clarke       23     single

Answered By: sammywemmy

Answer 6

You can use add_prefix or add_suffix as you need. To skip renaming some columns, you can set them as indexes and reset index after renaming.

If you want to exclude "ID" from renaming and add prefix "pre_"

df.set_index(['ID']).add_prefix("pre_").reset_index()

Derived from wwnde’s answer here : https://stackoverflow.com/a/70311963/17674957

Answered By: edzyldrm

How to add suffix to column names except some columns?

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