# Noemi Cabrera # 1 November 2021 # In this lesson, I learned how to use the .extend(), +, .reverse(), reversed(), sorted(), # and .sort() methids with lists. These are very helpful depending if you want to add a # list to another, remove an item, sort alphabetically or numerically the items in a list, # or reverse the order of the items in a list. # I had difiulties with Task 3:sort() & sorted(). I coudn't print the cities that started # with the letter Q or earlier. To fix this, I checked if the start index of each city was # 'Q'or any letter before it using an if/else statement.

# [ In this code, the extend method is used to add two lists together to form a new list. # The list of wish cities is added to the list of visited cities. This can be done with # the + sign too. ] review and run example visited_cities = ["New York", "Shanghai", "Munich", "Toyko", "Dubai", "Mexico City", "São Paulo", "Hyderabad"] wish_cities = ["Reykjavík", "Moscow", "Beijing", "Lamu"] # .extend() # extending visited_cities list (IN PLACE) by concatenating wish_cities visited_cities.extend(wish_cities) print("ALL CITIES",visited_cities)

# [ In this code, the visited cities list and wish cities list are added together using # the + sign and the new list is stored in the all_cities variable. Then, using the # for..in loop, each item in the all_cities list is printed in a new line. ] review and run example visited_cities = ["New York", "Shanghai", "Munich", "Toyko", "Dubai", "Mexico City", "São Paulo", "Hyderabad"] wish_cities = ["Reykjavík", "Moscow", "Beijing", "Lamu"] # (+) Addition operator for lists creates a (NEW) combined List all_cities = visited_cities + wish_cities print("ALL CITIES") for city in all_cities: print(city)

# [In this code , the lists tam_a & team_b are added together to form the new team_totals # list using the + sign. The originals list and the new list are printed. ] review and run example team_a = [0,2,2,2,4,4,4,5,6,6,6] team_b = [0,0,0,1,1,2,3,3,3,6,8] print("Team A:", team_a, "\nTeam B:",team_b) # (+) Addition operator team_totals = team_a + team_b print("Team Totals", team_totals)

# [ In this code, the team_a list is added team_b to form a new or modified list with the # extend method. The new list is printed. ] review and run example after running cell above # .extend() team_a.extend(team_b) print("Team_a extended", team_a) # what happens if you keep running this cell? # If you keep running this cell the team_a list keeps extending wibecause the list team_b # is added each time,

# [ In this code, the common_birds list and the birds_seen list are combined using the # extend method. The common_birds list is modified by adding the items from the bird_seen # list. The updated list is printed.] extend the list common_birds with list birds_seen # which you must create common_birds = ["chicken", "blue jay", "crow", "pigeon"] birds_seen = ["owl","eagle","hummingbird","gull"] common_birds.extend(birds_seen) print("Updated bird list:", common_birds)

# In this code, the zero_nine and ten_onehundred lists are deifned with only integer data. # These are added together by using the + sign and astored in the all_num variable. # The new list is printed. # [ ] Create 2 lists zero_nine and ten_onehundred that contain 1-9, and 10 - 100 by 10's. # [ ] use list addition to concatenate the lists into all_num and print zero_nine = [1,2,3,4,5,6,7,8,9] ten_onehundred = [10,20,30,40,50,60,70,80,90,100 ] all_num = zero_nine + ten_onehundred print(all_num)

# [ In this code, the list of cities is reversed in place by using the .reverse() method. # The list itself is modified and you cannot access the orginal one once you reverse it.] # review and run example cities_1 = ["Dubai", "Mexico City", "São Paulo", "Hyderabad"] print("regular", cities_1) cities_1.reverse() print("reversed", cities_1)

# [ In this code, the list all_num made up of integers is reversed with the .reverse() method. Then, a for..in loop is used to find the multiples # of 3 in the the reverse list. The if/else checks if the numbers are divisible by 3 and # prints the ones that are multiples of 3. ] review and run example all_num = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100] print("regular list",all_num, "\n") all_num.reverse() print("reverse list",all_num, "\n") num_len = len(all_num) print("Three Multiple") for num in all_num: if num/3 == int(num/3): print(num) else: pass

# [ In this code, the count _list is created by casting the range 0-20 into a list. # Then this list is reversed using the .reverse() method and printed using print() ] # review and run example # create a list of numbers by casting a range count_list = list(range(21)) print("before list", count_list) # and reverse count_list.reverse() print("after list", count_list)

# In this code, the five_m list contains the integers that are multiples of 5 from 5 to 100. # The original list is printed and then this list is reversed by using the reverse() # method. The five_m modified list is printed. # [ ] create and print a list of multiples of 5 from 5 to 100 # { ] reverse the list and print five_m = [5,10,15,20,25,30,35,30,45,50,60,70,80,85,90,95,100] print("orginal list:",five_m, "\n") five_m.reverse() print("reverse list",five_m, "\n")

# In this code, the fours & more_fours lists contains the integers that are multiples of 4 # from 4 to 44. To create a mirror effect in the output, I reverse the fours_list and then # combined the two lists together by using the + sign. The all_fours list is printed. # [ ] Create two lists: fours & more_fours containing multiples of four from 4 to 44 # [ ] combine and print so that the output is mirrored [44, 40,...8, 4, 4, 8, ...40, 44] fours = [4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44] more_fours = [4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44] fours.reverse() all_fours = fours + more_fours print(all_fours)

# [ In this code, the quiz_scores list, which contains a list of integers, is sorted # numerically from smallest to largest number. The .sort() method changes the original # list, so we cannot access the original list again. ] review and run example quiz_scores = [20, 19, 20, 15, 20, 20, 20, 18, 18, 18, 19] # use .sort() quiz_scores.sort() print("quiz_scores:", quiz_scores)

# [ IN this code, the srted() function is used with the game_points integer list. This # function doesn't change the orginal list, so we can ccess the orginal later. The new # sorted list, sorted_points, is created. ] review and run example game_points = [3, 14, 0, 8, 21, 1, 3, 8] # use sorted() sorted_points = sorted(game_points) print("game_points:", game_points) print("sorted_points:", sorted_points)

# [ In this code, the cities_1 list, which contains a list of strings, is sorted # alphabetically. The .sort() method changes the original list, so we cannot access the # original list again. ] review and run example cities_1 = ["Dubai", "Mexico City", "São Paulo", "Hyderabad"] print("Unsorted", cities_1) cities_1.sort() print("Sorted", cities_1)

# [ ] print cites from visited_cities list in alphbetical order using .sort() # [ ] only print cities that names start "Q" or earlier visited_cities = ["New York", "Shanghai", "Munich", "Toyko", "Dubai", "Mexico City", "São Paulo", "Hyderabad"] visited_cities.sort() print("List in alphabetical order:", visited_cities) for city in visited_cities: if city[0] <= "Q": print(city) else: pass

# In this code, a sorted version of the visited cites list is created and stored in # sorted_cities. Using a for..in loop, I checked if the lenght of each city was 5 or less. # If it was, the city was removed from the srted_cities list using the .remove() method. # If not, they were kept in the list. # [ ] make a sorted copy (sorted_cities) of visited_cities list # [ ] remove city names 5 characters or less from sorted_cities # [ ] print visitied cites and sorted cities visited_cities = ["New York", "Shanghai", "Munich", "Toyko", "Dubai", "Mexico City", "São Paulo", "Hyderabad"] sorted_cities = sorted(visited_cities) for city in visited_cities: if len(city) <= 5: sorted_cities.remove(city) else: pass print(visited_cities) print(sorted_cities)

# [ ] build a list (add_animals) using a while loop, stop adding when an empty string is entered add_animals = [] while True: animal = input("Enter an animal name: ").title() if animal != '': add_animals.append(animal) else: break

# [ ] extend the lists into animals, then sort animals = ["Chimpanzee", "Panther", "Wolf", "Armadillo"] animals.extend(add_animals) animals.sort()

# [ ] get input if list should be viewed alpha or reverse alpha and display list a_or_r = input("Enter 'alpha' for alphabetical order or 'reverse' for reverse order:") if a_or_r == 'alpha': print(animals) else: animals.reverse() print(animals)

# This program gets user input for an animal name repeatedly until a blank string is # entered. The names entered are added to an existing list. Then, the user is asked to # enter if he wants the list in just alphabetical order or reversed. The final list is # printed. add_animals = [] while True: animal = input("Enter an animal name or '' to finish: ").title() if animal != '': add_animals.append(animal) else: break animals = ["Chimpanzee", "Panther", "Wolf", "Armadillo"] animals.extend(add_animals) animals.sort() a_or_r = input("Enter 'alpha' for alphabetical order list or 'reverse' for reverse order list:") if a_or_r == 'alpha': print(animals) else: animals.reverse() print(animals)