I have checklist form data coming into a spreadsheet that I am trying to determine if a specific value was not checked and provide info based off that. My first thought was to have a master list/df where all the form values are then do a left/right merge on each response to determine values that weren't there.

Sample data and script. Expecting `nan/NA` for the missing Address response in the second set, with 6 rows instead of the original 5.

```
import pandas as pd
df_responses = pd.DataFrame({'Timestamp' : ['2022-09-21 10:39:40.676','2022-09-22 10:28:57.753'],
                            'Email': ['j@gmail.com', 'm@gmail.com'],
                            'Responses' : [['Name', 'Address', 'City'],['Name','City']]})

df_responses_expanded = df_responses.explode('Responses')

possible_responses = ['Name','Address','City']

df_possible_responses = pd.DataFrame({'responses_all':possible_responses})

df_check_responses = pd.merge(df_possible_responses,df_responses_expanded,how='left',left_on='responses_all',right_on='Responses')

```