$ ipython --version
6.1.0
$ jupyter --version
4.3.0
$ python --version
Python 3.6.2 :: Anaconda custom (64-bit)

pd.__version__

'0.20.3'

import pandas as pd
df = pd.DataFrame({'A':[1,2,3,4,5], 'B':[1,2,None,None,5], 'C':[None, None, 3, None, 4]})
print(df.isnull().sum())
print('---')
print(df.isnull().sum(axis=1))

A    0
B    2
C    3
dtype: int64
0    1
1    1
2    1
3    2
4    0
dtype: int64