Pandas How To Replace Values Based On Conditions For Several Values

I have a Dataframe with several column and below is first 3 columns in that dataframe: data_df = pd.DataFrame({'id':['era','bb','cs','jd','ek','gtf','okg','huf','mji','loj','djjf',

Solution 1:

Create a dict for mapping -

dict1 = dict(zip(range(1, 11), range(10,0,-1)))
data_df['dif'] = data_df['dif'].map(dict1)

Solution 2:

new_df = data_df.assign(dif=11 - data_df['dif'])

Or, if you want to do it in place:

data_df['dif'] = 11 - data_df['dif']

Solution 3:

It's really simple:

>>> data_df["dif"] = 11 - data_df["dif"]
>>> data_df
      id    doc  dif
0    era   1050   10
1     bb    580   10
2     cs    170   10
3     jd      8    8
4     ek      7    8
5    gtf    220    9
6    okg  45155    9
7    huf    305    8
8    mji    458    7
9    loj    201    6
10  djjf     48    3
11  wloe     78    4
12   rfm    256    2
13   cok    358    1

or replace 11 by data_df["dif"].max() + 1