Stable_Matching.py

# Initialization
Men = ['Mike', 'Harvey', 'Louis', 'Logan']
Women = ['Rachel', 'Donna', 'Katrina', 'Sheila']

# Preferences
Men_Pref = {  # indicates the preferences of the men
    'Mike':   ['Rachel', 'Katrina', 'Donna', 'Sheila'],
    'Harvey': ['Donna', 'Katrina', 'Rachel', 'Sheila'],
    'Louis':  ['Sheila', 'Donna', 'Katrina', 'Rachel'],
    'Logan':  ['Rachel', 'Katrina', 'Donna', 'Sheila']
}

Women_Pref = {  # indicates the preferences of the women
    'Rachel':  ['Mike', 'Logan', 'Harvey', 'Louis'],
    'Donna':   ['Harvey', 'Louis', 'Mike', 'Logan'],
    'Katrina': ['Mike', 'Harvey', 'Louis', 'Logan'],
    'Sheila':  ['Louis', 'Logan', 'Harvey', 'Mike']
}
def main():
    Men_Free = list(Men)
    Women_Free = list(Women)

    # Part 3: Proposal
    Matches = {
        'Mike':  '',
        'Harvey': '',
        'Louis': '',
        'Logan': ''
        }
    key_list = list(Matches.keys())

    # the algorithm

    while len(Men_Free) > 0:
        for man in key_list:
            for woman in Men_Pref[man]:
                if woman not in list(Matches.values()):
                    Matches[man] = woman
                    Men_Free.remove(man)
                    print('{} is no longer a free man and is tentatively engaged to {} !'.format(man, woman))
                    break
                elif woman in list(Matches.values()):
                    current_suitor = list(Matches.keys())[list(Matches.values()).index(woman)]
                    w_list = Women_Pref.get(woman)
                    if w_list.index(man) < w_list.index(current_suitor):
                        Matches[man] = woman
                        Men_Free.remove(man)
                        Matches[current_suitor] = ''
                        Men_Free.append(current_suitor)
                        print('{} was earlier engaged to {} but now is engaged to {}! '.format(woman, current_suitor, man))

    print('\n ')
    print('Stable Matching Finished ! Happy engagement !')
    for man in Matches.keys():
        print('{} is engaged to {} !'.format(man, Matches[man]))


if __name__ == "__main__":
    main()