CODEWITHSUNDEEP
pythonpandas
runningbirds
runningbirds

Reputation: 6615

multiply two pandas data frames together using corresponding column names

I have pandas data frames which share at least some common column names. The position of the column names is not guaranteed to be the same, but I want to multiply them together if they share a common name.

For example, in data frame "A" income may be the 3rd column but in data frame "B" income could be the 11th column. Is there a way I can multiply these together using common column names?

df1=pd.DataFrame({'a':[1,3,5],'c':[10,20,40],'b':[8,6,4]})
df2=pd.DataFrame({'b':[1,33,5],'a':[10,200,7],'c':[0,6,1]})

I'd like to multiply these together. Positions of each columns are never guaranteed to be in the same spot. Any 'smart' ways? To do this.

I had put together code where I would look for the intersection of column names and then sort them alphabetically and then multiply, but I'm figuring there is something a bit more intelligent?

Sorry if this is too obvious of a question, I just figure there has to be something smart out there in pandas that doesn't require me writing 20 lines of code.

Upvotes: 1

Views: 635

Answers (3)

RichieV
RichieV

Reputation: 5183

You can do something like

df3 =pd.DataFrame() 
for colname in df1.columns:
    df3[colname] = df1[colname] * df2[colname]

This is useful of there are more columns in df1 and df2

Upvotes: 0

Prayson W. Daniel
Prayson W. Daniel

Reputation: 15568

You can just multiply them. As long as they have the same columns name and rows number

import pandas as pd

df1=pd.DataFrame({'a':[1,3,5],'c':[10,20,40],'b':[8,6,4]})
df2=pd.DataFrame({'b':[1,33,5],'a':[10,200,7],'c':[0,6,1]})

df = df1 * d2

print(df)

Results enter image description here

Upvotes: 1

Marcos Tidball
Marcos Tidball

Reputation: 36

I think this isn't the most efficient way to do this, but is something that would work:

name = "income"

for col1 in df1.columns:
    for col2 in df2.columns:
        if (col1 == name) and  (col2 == name):
            multiplied = df1[col1] * df2[col2]

Where multiplied is a series.

Upvotes: 0

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