pandas - Python: Divide each row of a DataFrame by another DataFrame vector

Question

I have a DataFrame (df1) with a dimension 2000 rows x 500 columns (excluding the index) for which I want to divide each row by another DataFrame (df2) with dimension 1 rows X 500 columns. Both have the same column headers. I tried:

df.divide(df2) and df.divide(df2, axis='index') and multiple other solutions and I always get a df with nan values in every cell. What argument am I missing in the function df.divide?

Answer 1

In df.divide(df2, axis='index'), you need to provide the axis/row of df2 (ex. df2.iloc[0]).

import pandas as pd

data1 = {"a":[1.,3.,5.,2.],
         "b":[4.,8.,3.,7.],
         "c":[5.,45.,67.,34]}
data2 = {"a":[4.],
         "b":[2.],
         "c":[11.]}

df1 = pd.DataFrame(data1)
df2 = pd.DataFrame(data2) 

df1.div(df2.iloc[0], axis='columns')

or you can use df1/df2.values[0,:]