Add 2 new columns to existing dataframe using apply

Question

I want to use the apply function that: - Takes 2 columns as inputs - Outputs two new columns based on a function.

An example is with this add_multiply function.

Answer 1

anky_91's answer highlights a useful option in apply.

For this particular case however, apply is not even required,

df['add'], df['multiply'] = add_multiply(df['col1'],df['col2'])