replace the another column value based on one column is not null pandas code example

Example 1: pandas replace null values with values from another column

#Python
#Col 1 = where you want the values replaced
#Col 2 = where you want to take the values from
df.["Col 1"].fillna(df.["Col 2"], inplace=True)

Example 2: replace value column by another if missing pandas

import numpy as np

df['column'] = np.where(df['column'].isnull(), 'value_if_true', 'value_if_false')