Pandas - Creating Difference Matrix from Data Frame

Question

I\'m trying to create a matrix to show the differences between the rows in a Pandas data frame.

import pandas as pd

data = {\'Country\':[\'GB\',\'JP\',\'US\         


        

Answer 1

Option 1

from itertools import product
import pandas as pd
DF=pd.DataFrame(list(product(df.Country, df.Country)), columns=['l1', 'l2'])
df=df.set_index('Country')
DF['v1']=DF.l1.map(df['Values'])
DF['v2']=DF.l2.map(df['Values'])
DF['DIFF']=DF['v2']-DF['v1']
DF.pivot(index='l1', columns='l2', values='DIFF').fillna(0).rename_axis(None).rename_axis(None,1)
Out[94]: 
      GB    JP    US
GB   0.0 -30.7 -14.5
JP  30.7   0.0  16.2
US  14.5 -16.2   0.0

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Option 2 using apply

A=df['Values'].apply(lambda x : df['Values']-x)
A.columns=df.Country
A['Country']=df.Country


A
Out[124]: 
Country    GB    JP    US Country
0         0.0 -30.7 -14.5      GB
1        30.7   0.0  16.2      JP
2        14.5 -16.2   0.0      US