df.isna().sum()
In [5]: df = pd.DataFrame({'a':[1,2,np.nan], 'b':[np.nan,1,np.nan]}) In [6]: df.isna().sum() Out[6]: a 1 b 2 dtype: int64
dfObj.isnull().sum()
cols_to_delete = df.columns[df.isnull().sum()/len(df) > .90] df.drop(cols_to_delete, axis = 1, inplace = True)
dfObj.isnull().sum().sum()