# Noemi Cabrera # 29 October 2021 # In this lesson, I learned how to delete items from a list with del, .pop() & .remove(). The del # statement goes before the specified index you want to remove from a list. The pop method both removes # and returns an item from list. In this method, you would place the item you to delete in pop(). # Lastly,the remove mothod deletes the 1st item that matches the item you wnat to delete in a list. # In this method, you would place the item you to delete in remove(). # I didn't have any difficulties in this lesson.

# [In this case, the delete command is used to delete the item at index 1 in the sample list. The keyword # del is placed in front of the slice made at index 1 to the list. ] review and run example # the list before delete sample_list = [11, 21, 13, 14, 51, 161, 117, 181] print("sample_list before: ", sample_list) del sample_list[1] # the list after delete print("sample_list after: ", sample_list)

# [ In this case, the delete command is used to delete the item at index 0 in the sample list. The keyword # del is placed in front of the slice made at index 0 to the list. ] review and run example Multiple Times # [ ] consider how to reset the list values? print("sample_list before:", sample_list) del sample_list[0] print("sample_list after:", sample_list)

# [ In this code, the mixed_types list is appended 2 more items by using the .append() method. The list # contains a mix of strings and integers. ] review and run example mixed_types = [1, "cat"] # append number mixed_types.append(3) print("mixed_types list: ", mixed_types) # append string mixed_types.append("turtle") print("mixed_types list: ", mixed_types)

# In this case, the delete command is used to delete the item at index 2 in the ft_bones list. Both the # orginal and new list are printed. # [ ] print ft_bones list # [ ] delete "cuboid" from ft_bones # [ ] reprint list ft_bones = ["calcaneus", "talus", "cuboid", "navicular", "lateral cuneiform", "intermediate cuneiform", "medial cuneiform"] print(ft_bones) del ft_bones[2] print(ft_bones)

# In this case, the delete command is used to delete the items at index 2 and index 3 in the ft_bones list. # Te if/else statement checks if the items in the ft_bones were deleted. If they were not, then an # statement saying so will display. # Both the orginal and new list are printed. # [ ] print ft_bones list # [ ] delete "cuboid" from ft_bones # [ ] delete "navicular" from list # [ ] reprint list # [ ] check for deletion of "cuboid" and "navicular" ft_bones = ["calcaneus", "talus", "cuboid", "navicular", "lateral cuneiform", "intermediate cuneiform", "medial cuneiform"] print(ft_bones) del ft_bones[2] del ft_bones[3] print(ft_bones) if ft_bones[2] == "cuboid": print("3rd item not deleted") else: print("3rd item deleted") if ft_bones[3] == "navicular": print("4th item not deleted") else: print("4th item deleted")

# [ In this code the pop method is used to delete an item from the party list. Since no index is specified, # the pop method by default deletes and returns the last item in the list 3 times. Because there are 3 # items in the party list, the list would be empty at the end.] review and run example # pop() gets the last item by default party_list = ["Joana", "Alton", "Tobias"] print(party_list) print("Hello,", party_list.pop()) print("\n", party_list) print("Hello,", party_list.pop()) print("\n", party_list) print("Hello,", party_list.pop()) print("\n", party_list)

# [ ] review and run example # can pop specific index like pop(3) number_list = [11, 21, 13, 14, 51, 161, 117, 181] print("before:", number_list) number_list.pop(3) print("after :", number_list)

# [In this code, the pop method is used within two variables. Since an index is not specified, the pop # method both removes and returns the last item in the list. SInce this happens twice, the last 2 items # are removed and returned from the list. Then these are used individually in a print statement. ] # review and run example # set a variable to a poped value number_list = [11, 21, 13, 14, 51, 161, 117, 181] print("list before:", number_list) num_1 = number_list.pop() num_2 = number_list.pop() print("list after :", number_list) print("add the popped values:", num_1, "+", num_2, "=", num_1 + num_2)

# [ To both remove and return the first item in the ft_bones list, I placed the pop() method with the # ft_bones list and specified it removes index 0. To both remove and return the last item in the ft_bones # list, I placed the pop() method empty ] pop() and print the first and last items from the # ft_bones list ft_bones = ["calcaneus", "talus", "cuboid", "navicular", "lateral cuneiform", "intermediate cuneiform", "medial cuneiform"] print(ft_bones.pop(0)) print(ft_bones.pop()) # [ The final list is printed ] print the remaining list print(ft_bones)

# In this example, the pop method is used in while condition. This removes and returns every item in the # list statrting from teh last one until the list is empty because the while condition evaluates false # when there is no list. dog_types = ["Lab", "Pug", "Poodle"] while dog_types: print(dog_types.pop())

#[ In this cash register code, the user is asked to enter the price of an item or 'done' to finsh the # list. The while loop runs until the word "done" is entered by the user. The user input is added to the # purchase_amounts empty list. ] complete the Register Input task above purchase_amounts = [] while True: item_price = input("Enter the price of item or 'done' to finish: ") if item_price != 'done': purchase_amounts += item_price else: print(purchase_amounts) break

# [ This cash register subtotal code uses the input and code from Task 3 above to calculate the total of # the prices entered by the user. Each price entered by the user in a list is removed and returned to # find the total using the pop method. ] complete the Register Total task above subtotal = 0 while purchase_amounts != []: float_price = float(purchase_amounts.pop()) subtotal += float_price print(subtotal)

# [ In this code, the remove mothod is used to remove an item from the list dog_types. The item you want # to remove is placed in between the parentheses of .absremove(). If the item is not found in the list an # error will display. ] review and run example dog_types = ["Lab", "Pug", "Poodle"] if "Pug" in dog_types: dog_types.remove("Pug") else: print("no Pug found") print(dog_types)

# [ In this code, the remove mothod is used to remove "Poodle" from the dogs list. Since there are # multiple "Poodle" strings the while loop is used to delete it until there are none left in the dogs # list. The list is printed to show the items left in the list each time.] review and run example dogs = ["Lab", "Pug", "Poodle", "Poodle", "Pug", "Poodle"] print(dogs) while "Poodle" in dogs: dogs.remove("Poodle") print(dogs)

# [ This code displays an error becaus the string "Collie" that wants to be removed from the dogs list # is not found the list. To fix this, you need to remove an item that is in the list.] review and run # example # Change to "Lab", etc... to fix error dogs.remove("Collie") print(dogs)

# [ Since the remove mothod deletes the 1st item that matches, I used it once in this code to delete # "Poodle" one time. If "Poodle is in the dogs list, then the 1st Poodle in the list is deleted. # If Poodle is not found in the list, then a statement saying so displays."] # remove one "Poodle" from the list: dogs , or print "no Poodle found" # [ ] print list before and after dogs = ["Lab", "Pug", "Poodle", "Poodle", "Pug", "Poodle"] print(dogs) if "Poodle" in dogs: dogs.remove("Poodle") print(dogs) else: print("no Poodle found")