How to approach simple recursion in python -

i've been trying understand recursion/recursivity in programming languages , i've chosen work python, since it's language understand most. i've tried resolving following problem -

given 3 different lists of elements, find possible patterns person has followed during shopping day.

lists

purchases = [[money_spent, time0], [money_spent, time1], [money_spent, time3]]  time_between_shops = [[time_to_self, time_to_shop2, time_to_shop3, time_to_shop4],                      [time_to_shop1, time_to_self, time_to_shop3, time_to_shop4],                      [time_to_shop1, time_to_shop2, time_to_self, time_to_shop4],                      [time_to_shop1, time_to_shop2, time_to_shop3, time_to_self]]  list_of_products = [["shop1", {"product1": price_of_product1, "product2": price_of_product2}],                     ["shop2", {"product3": price_of_product3, "product4": price_of_product4, "product5": price_of_product5}],                     ["shop3", {"product6": price_of_product6}],                     ["shop4", {"product7": price_of_product7}]] 

in lists purchases ordered time (earliest latest purchase) , shops have same indexes in list_of_products in time_between_shops. time between shops can same, time takes go shop shop b can different time takes go shop b shop a. given time in minutes 0 0:00 , 1439 23:59.

given information, know how approach problem regular way, need use recursive methods obtain possibilities. i've read on recursive methods, know represent, , when see 1 can understand , how works, when comes creating recursive methods on own, lost since go regular methods.

so how should approach problem in order resolve using recursion instead of regular methods?