在字典中查找具有相同值的嵌套列表[Python]

Question

Currently have a Dictionary that is structured as such

data =
{
     "Invitees": [
    {
           "firstName": "Will",
           "lastName": "Klein",
           "email": "WKlein@***il.com",
           "highSchool": "NorthwestHS",
           "availableDates": [
               "2018-02-01",
               "2018-02-02"
           ]
     },
     {
           "firstName": "Jack",
           "lastName": "Smith",
           "email": "JSmith@***il.com",
           "highSchool": "SouthwestHS",
           "availableDates": [
                "2018-02-04",
                "2018-01-01"
            ]
     },
     {
           "firstName": "Jamie",
           "lastName": "Farough",
           "email": "JFarough@***il.com",
           "highSchool": "NorthwestHS",
           "availableDates": [
                "2018-02-01",
                "2018-02-02"
           ]
     },
     {
           "firstName": "Bob",
           "lastName": "Saggot",
           "email": "BSaggot@***il.com",
           "highSchool": "NorthwestHS",
           "availableDates": [
               "2018-02-01",
               "2018-02-02"
           ]
     }
  ]
}

I want to invite people to my 2-day Birthday Party, but I have to pick a date that best works for the individuals (indexed by their HS). The goal is create a program that can index the Dictionary and return which people can attend based on the dates their availability (2 consecutive days). Right now I created a list detailing the information of each person, but am not sure how to combine them by their available dates. I have:

for index in range(lengthofDic):
     highSchool.append(data["Attendee"][index]["highSchool"])
     email.append(data["Attendee"][index]["email"])
     availDate.append(data["Attendee"][index]["availableDates"])

Which gives the different list containing the information for each person, but I dont know how to combine and filter the list in order to find the best 2 dates that work for people at the same school.

Also tried a function below to filter out the same dates between different values in the list, but dont know how to do it for more than 2 list:

 for index in range(lengthofDic):
      print (lamda x,y: x in (availableDate[1]), (availableDate[1]))  #availableDate is list containing dates

An example of the output that I would want is below:

{
    "Attendee": [
    {
        "aCount": 3,
        "attendees": [
            "BSaggot@***il.com"                
            "JFarough@***il.com"
            "WKlein@***il.com
        ],
        "highSchool": "NorthwestHS",
        "startDate": "2018-02-01"
    },
    {
        "aCount": 0,
        "attendees": [],
        "highSchool": "SouthWestHS,
        "startDate": null
    }

Southwest High School could not attend because the attendee(s) from that school did not have any consecutive 2 day availability so it returned NULL. Any advice on how to structure the program or what methods to use would be greatly appreciated!!

Answer 1

You can use itertools.groupby :

import itertools
data = {'Invitees': [{'availableDates': ['2018-02-01', '2018-02-02'], 'lastName': 'Klein', 'highSchool': 'NorthwestHS', 'email': 'WKlein@***il.com', 'firstName': 'Will'}, {'availableDates': ['2018-02-04', '2018-01-01'], 'lastName': 'Smith', 'highSchool': 'SouthwestHS', 'email': 'JSmith@***il.com', 'firstName': 'Jack'}, {'availableDates': ['2018-02-01', '2018-02-02'], 'lastName': 'Farough', 'highSchool': 'NorthwestHS', 'email': 'JFarough@***il.com', 'firstName': 'Jamie'}, {'availableDates': ['2018-02-01', '2018-02-02'], 'lastName': 'Saggot', 'highSchool': 'NorthwestHS', 'email': 'BSaggot@***il.com', 'firstName': 'Bob'}]}
new_data = [(a, list(b)) for a, b in itertools.groupby(sorted(data['Invitees'], key=lambda x:int(x['availableDates'][-1].split('-')[-1])-int(x['availableDates'][0].split('-')[-1]), reverse=True), key=lambda x:int(x['availableDates'][-1].split('-')[-1])-int(x['availableDates'][0].split('-')[-1]))]
final_students = {'Attendee':[{"aCount":len(b), "attendees":[c['email'] for c in b], "highschool":[c['highSchool'] for c in b][0], "startDate":[c['availableDates'][0] for c in b][0]} if a == 1 else {'aCount':0, 'attendees':[], 'highschool':[i['highSchool'] for i in b][0], 'startdate':None} for a, b in new_data]}

Output:

{'Attendee': [{'aCount': 3, 'startDate': '2018-02-01', 'highschool': 'NorthwestHS', 'attendees': ['WKlein@***il.com', 'JFarough@***il.com', 'BSaggot@***il.com']}, {'aCount': 0, 'startdate': None, 'highschool': 'SouthwestHS', 'attendees': []}]}