Answers for "display the null values percentage against every column in a dataframe"

pandas determine percentage of nans in column

>>> flights.isna().mean().round(4) * 100

How many columns have null values present in them? in pandas

import pandas as pd
df = pd.DataFrame({'a':[1,2,np.nan], 'b':[np.nan,1,np.nan],'c':[np.nan,2,np.nan], 'd':[np.nan,np.nan,np.nan]})
print(pd.isnull(df).sum())