Pandas Data Frame Partial String Replace

Question

Given this data frame:

import pandas as pd
d=pd.DataFrame({'A':['a','b',99],'B':[1,2,'99'],'C':['abcd99',4,5]})
d

    A   B   C
0   a   1   abcd*
1   b   2   4
2   99  99  5

I want to replace all 99s in the entire data frame with asterisks. I've tried this:

d.replace('99','*')

...but it only worked in the case of the string 99 in column B.

Thanks in advance!

Answer 1

Use numpys character functions

d.values[:] = np.core.defchararray.replace(d.values.astype(str), '99', '*')
d

   A  B      C
0  a  1  abcd*
1  b  2      4
2  *  *      5

naive time test