df.isnull().values.any()
df['your column name'].isnull().values.any()
df['your column name'].isnull().sum()
In [1]: s = pd.Series([1,2,3, np.nan, np.nan]) In [4]: s.isna().sum() # or s.isnull().sum() for older pandas versions Out[4]: 2
df.isnull().sum().sum()