What is this declaration? lists are declared using [ but these contain key-value pairs as seen with the use of {}. It's confusing. list with {} brackets with a pair of two items forming one. players = [ {"name": "Rolf", "numbers": {1, 3, 5, 7, 9, 11}}, {"name": "Charlie", "numbers": {2, 7, 9, 22, 10, 5}}, {"name": "Anna", "numbers": {13, 14, 15, 16, 17, 18}}, {"name": "Jen", "numbers": {19, 20, 12, 7, 3, 5}} ] How does player in players have a "numbers" index? for player in players: # Go over each player matched_numbers = len(player["numbers"].intersection(lottery_numbers)) and how does the len function work? Continue reading...
