Replace a particular string in a column with strings in another column in Pandas

Question

I wonder how to replace the string value of 'Singapore' in location1 column with the string values from location2 column. In this case, they're Tokyo, Boston, Toronto and Hong Kong, Boston.

import pandas as pd
data = {'location1':["London, Paris", "Singapore", "London, New York", "Singapore", "Boston"], 
        'location2':["London, Paris", "Tokyo, Boston, Toronto", "London, New York", "Hong Kong, Boston", "Boston"]}

df = pd.DataFrame(data)

          location1               location2
0     London, Paris           London, Paris
1         Singapore  Tokyo, Boston, Toronto
2  London, New York        London, New York
3         Singapore       Hong Kong, Boston
4            Boston                  Boston

Corralien · Accepted Answer · 2021-12-01 14:05:47Z

2

Simply, use .loc and indexing:

df.loc[df['location1'].eq('Singapore'), 'location1'] = df['location2']
print(df)

# Output:
                location1               location2
0           London, Paris           London, Paris
1  Tokyo, Boston, Toronto  Tokyo, Boston, Toronto
2        London, New York        London, New York
3       Hong Kong, Boston       Hong Kong, Boston
4                  Boston                  Boston

answered Dec 1, 2021 at 14:05

Corralien

121k8 gold badges43 silver badges68 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

tlentali · Accepted Answer · 2021-12-01 14:01:38Z

2

We can do it using the numpy.where method :

>>> import numpy as np
>>> df["location1"] = np.where(df["location1"] == 'Singapore', df["location2"], df["location1"])
>>> df
    location1               location2
0   London, Paris           London, Paris
1   Tokyo, Boston, Toronto  Tokyo, Boston, Toronto
2   London, New York        London, New York
3   Hong Kong, Boston       Hong Kong, Boston
4   Boston                  Boston

answered Dec 1, 2021 at 14:01

tlentali

3,4632 gold badges18 silver badges23 bronze badges

Comments

Scott Boston · Accepted Answer · 2021-12-01 14:01:50Z

1

Try:

df['location1'] = df['location1'].mask(df['location1'] == 'Singapore')\
                                 .fillna(df['location2'])

Output:

                location1               location2
0           London, Paris           London, Paris
1  Tokyo, Boston, Toronto  Tokyo, Boston, Toronto
2        London, New York        London, New York
3       Hong Kong, Boston       Hong Kong, Boston
4                  Boston                  Boston

answered Dec 1, 2021 at 14:01

Scott Boston

154k15 gold badges160 silver badges207 bronze badges

Collectives™ on Stack Overflow

Replace a particular string in a column with strings in another column in Pandas

3 Answers 3

Comments

Comments

Comments

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Related