replace nan with other column pandas code example

Example 1: replace nan in pandas

df['DataFrame Column'] = df['DataFrame Column'].fillna(0)

Example 2: how to replace nan with 0 in pandas

df['product']=df['product'].fillna(0)
df['context']=df['context'].fillna(0)
df

Example 3: 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)