How to assign a new descriptive column while concatenating data frames in python

user_12746134 0
Viewed 190

I have two data frames that i want to concatenate in python. However, I want to add another column type in order to distinguish among the columns.

Here is my sample data:

import pandas as pd
df = pd.DataFrame({'numbers': [1, 2, 3], 'colors': ['red', 'white', 'blue']}, 
                  columns=['numbers', 'colors'])

df1 = pd.DataFrame({'numbers': [7, 9, 9], 'colors': ['yellow', 'brown', 'blue']}, 
                  columns=['numbers', 'colors'])
pd.concat([df,df1])

This code will give me the following result:

    numbers colors
0   1   red
1   2   white
2   3   blue
0   7   yellow
1   9   brown
2   9   blue

but what I would like to get is as follows:

  numbers colors  type
0   1   red       first
1   2   white     first
2   3   blue      first
0   7   yellow    second
1   9   brown     second
2   9   blue      second

type column is going to help me to differentiate between the values of the two data frames.

Can anyone help me with this please?

pandas concat dataframe merge python
1 Answers

Use DataFrame.assign for new columns:

df = pd.concat([df.assign(typ='first'),df1.assign(typ='second')])
print (df)
   numbers  colors     typ
0        1     red   first
1        2   white   first
2        3    blue   first
0        7  yellow  second
1        9   brown  second
2        9    blue  second
user_29010020
Related