How to pass two columns of a dataframe to a function in python?

Question

I am trying out this below code. But I am returned with the error

("Newmethod() missing 1 required positional argument: 'B'", 'occurred at index 0')

def Newmethod(A,B):
  Add=A+B
  return Add

Df=pd.DataFrame([[1,2,3],[4,5,6],[7,8,9]],columns=["A","B","C"])
Df['D']=Df[['A','B']].apply(Newmethod, axis=1)

What do I miss here? Please assist me.

Answer 1

Change it

Df['D']=Df[['A','B']].apply(lambda x:Newmethod(x.A,x.B), axis=1)

   A  B  C   D
0  1  2  3   3
1  4  5  6   9
2  7  8  9  15

Explain

You can use np.sum or change your Newmethod() . Otherwise, you can only do this in your form.

import numpy as np
Df['D']=Df[['A','B']].apply(np.sum, axis=1)
# or
def Newmethod(x):
    Add= x.A + x.B
    return Add
Df['D']=Df[['A','B']].apply(Newmethod, axis=1)