Replace string taken from another column in pandas

Question

I am trying to do a replace across one column of a pandas dataframe like the below.

From:

a          b
house      ho
cheese     ee
king       ng

To:

a        b
use      ho
chse     ee
ki       ng

My attempt is to use:

df['a'] = df['a'].str.replace(df['b'], "")

but I get TypeError: 'Series' objects are mutable, thus they cannot be hashed

I have done it by iterating row by row across the dataframe but its 200,000 rows so would take hours. Does anyone know how I can make this work?

jezrael · Accepted Answer · 2020-04-05 07:16:00Z

3

Because performance is important here is possible use list comprehension with replace for replace per rows:

df['a'] = [a.replace(b, "") for a, b in df[['a','b']].values]

Another solution is slowier with DataFrame.apply:

df['a'] = df.apply(lambda x: x.a.replace(x.b, ""), axis=1)

print (df)
      a   b
0   use  ho
1  chse  ee
2    ki  ng

answered Apr 5, 2020 at 7:16

jezrael

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