[FIXED] Replace all instances of a value for another

Issue

I have this part of the df

        x            y         d   n
0   -17.7    -0.785430  0.053884  y1
1   -15.0 -3820.085000  0.085000  y4
2   -12.5     2.138833  0.143237  y3
3   -12.4     1.721205  0.251180  y3

I want to replace all instances of y3 for "3rd" and y4 for "4th" in column n

Output:

        x            y         d   n
0   -17.7    -0.785430  0.053884  y1
1   -15.0 -3820.085000  0.085000  4th
2   -12.5     2.138833  0.143237  3rd
3   -12.4     1.721205  0.251180  3rd

Solution

Simple. You can use Python str functions after .str on a column.

df['n'] = df['n'].str.replace('y3', '3rd').replace('y4', '4th')

OR

You can select the specific columns and replace like this

df[df['n'] == 'y3'] = '3rd'
df[df['n'] == 'y4'] = '4th'

Choice is yours.

Answered By - pavi2410