l1=train. Index\[train\['Pclass'\]==1\]
train.iloc\[l1,5:6\].fillna(37,inplace=True)
train.iloc\[l1,5:6\].isnull().sum()
Why is the fillna function not filling na values?
I need to fill na values in column with specific values for specific indices.
e.g for l1 indices ,na need to be replace by 37
