cohorts.py

class Patient(object):
    def __init__(self, name, region, age):
        self.name = name
        self.region = region
        self.age = age

    def __repr__(self):
        return f'Person({repr(self.name)}, {repr(self.region)}, {repr(self.age)})'


class Cohort(object):
    def includes(self, patient):
        raise NotImplementedError('The Cohort class\'s includes method must be overridden to be called.')

    def filter(self, patients):
        result = []
        for patient in patients:
            if self.includes(patient):
                result.append(patient)
        return result


class RegionalCohort(Cohort):
    def __init__(self, region):
        self.region = region

    def includes(self, patient):
        return patient.region == self.region


class AgeCohort(Cohort):
    def __init__(self, minimum, maximum):
        self.minimum = minimum
        self.maximum = maximum

    def includes(self, patient):
        return self.minimum <= patient.age <= self.maximum


if __name__ == '__main__':
    ada = Patient('Ada', 'UK', 203)
    charles = Patient('Charles', 'UK', 227)
    grace = Patient('Grace', 'US', 112)
    all_patients = [ada, charles, grace]
    uk_cohort: Cohort = RegionalCohort('UK')
    young_cohort: Cohort = AgeCohort(0, 225)
    print(f'Charles is in the UK region: {uk_cohort.includes(charles)}')
    print(f'Charles is in the "young" age group: {young_cohort.includes(charles)}')
    print(f'Everyone in the UK region: {uk_cohort.filter(all_patients)}')
    print(f'Everyone in the "young" age group: {young_cohort.filter(all_patients)}')