python find proportion of missing values in dataframe code example

Example 1: pandas determine percentage of nans in column

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

Example 2: getting the number of missing values in pandas

cols_to_delete = df.columns[df.isnull().sum()/len(df) > .90]
df.drop(cols_to_delete, axis = 1, inplace = True)