missing values in a dataset python

1df.isnull().sum()

1df.T.fillna(df.mean(axis=1)).T

1note:to fill a specific value
2
3varable = 1
4def fill_mod_acc(most_related_coloum_name,missing_data_coloum):
5    if np.isnan(missing_data_coloum):
6        return varable[most_related_coloum_name]
7    else:
8        return missing_data_coloum
9
10df['missing_data_coloum'] = df.apply(lambda x:fill_mod_acc(x['most_related_coloum_name'],x['missing_data_coloum']),axis=1)
11
12
13Note:to fill mean from existing closley related coloum
14
15varable = df.groupby('most_related_coloum_name').mean()['missing_data_coloum']
16
17def fill_mod_acc(most_related_coloum_name,missing_data_coloum):
18    if np.isnan(missing_data_coloum):
19        return varable[most_related_coloum_name]
20    else:
21        return missing_data_coloum
22
23df['missing_data_coloum'] = df.apply(lambda x:fill_mod_acc(x['most_related_coloum_name'],x['missing_data_coloum']),axis=1)