python 中的正则表达式替换列值的最后两位数字，如果最后两位数字为 30，则将其替换为 50

Question

I have the following data frame

abc=pd.DataFrame()

abc['Col_A']=[1900,1200,1230,1130,1300,0330]
abc

    Col_A
0   1900
1   1200
2   1230
3   1130
4   1300
5   0330

from the above data frame I want to replace last two digits wherever I see 30 I want to replace it with 50

My expected output is below.

    Col_A
0   1900
1   1200
2   1250
3   1150
4   1300
5   0350

If not re than anything other than Regular expression will also be helpful. Thanks in advance

Answer 1

Assuming your Col_A values are actually strings, then we can use str.replace here:

df["Col_A"] = df["Col_A"].str.replace(r'30$', '50')

Note that values like 0330 will only retain their leading zeroes in the event that they are strings , and not integers, the latter which don't actually have any leading zeroes.

To cover the same logic with a numeric column, use:

df["Col_A"] = np.where(df["Col_A"] % 30 == 0, df["Col_A"] + 20, df["Col_A"])