post-1

flavor1.py

import pandas as pd
import pandas_flavor as pf

@pf.registor_dataframe_method
def check_columns(df):
    # Required columns
    required_cols = {'x', 'y', 'z'}

    # Find columns missing from 
    if required_cols.issubset(df.columns) is False:
          raise Exception('DataFrame is missing required columns. '
                          'Must have {}'.format(required_cols))