replace with null pandas code example

Example 1: pandas to convert null values to mean in numeric column

df.fillna(df.mean(), inplace=True)

Example 2: 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)