Step 5 - “Delete” option
New functions needed:
delete_dish()
Refer to the delete_item() function (from LAB 8.14) to see how to implement the function below. This is very similar (but not the same) as it was in the Week 8 lab.
def delete_dish(in_list, idx, start_idx=0):
"""
param: in_list - a list from which to remove a dish
param: idx (str) - a string that is expected to
contain a representation of an integer index
of a dish in the provided list
param: start_idx (int) - by default, set to 0;
an expected starting value for idx that
gets subtracted from idx for 0-based indexing
The function first checks if the input list is empty.
The function then calls is_valid_index() to verify
that the provided index idx is a valid positive
index that can access an element from in_list.
On success, the function saves the dish from in_list
and returns it after it is deleted from in_list.
returns:
If the input list is empty, return 0.
If idx is not of type string, return None.
If is_valid_index() returns False, return -1.
Otherwise, on success, the function returns the element
that was just removed from the input list.
Helper functions:
- is_valid_index()
"""
The main program portion should contain:
elif opt == 'D':
restaurant_menu_list = delete_helper(restaurant_menu_list, spicy_scale_map)
Complete the delete_helper given to you below:
def delete_helper(restaurant_menu_list, spicy_scale_map):
continue_action = 'y'
while continue_action == 'y':
if not restaurant_menu_list:
print("WARNING: There is nothing to delete!")
break
print("Which dish would you like to delete?")
print("Press A to delete the entire menu for this restaurant, M to cancel this operation")
print_restaurant_menu(restaurant_menu_list, spicy_scale_map, name_only=True, show_idx=True, start_idx=1)
user_option = input("> ")
if user_option == "A" or user_option == "a":
print(f"::: WARNING! Are you sure you want to delete the entire menu ?")
print("::: Type Yes to continue the deletion.")
user_option = input("> ")
if user_option == ...:
restaurant_menu_list = ...
print(f"Deleted the entire menu.")
else:
print(f"You entered '{...}' instead of Yes.")
print("Canceling the deletion of the entire menu.")
break
elif user_option == 'M' or user_option == 'm':
break
result = delete_dish(restaurant_menu_list, user_option, 1)
if type(result) == dict:
print("Success!")
print(f"Deleted the dish |{result['name']}|")
elif result == 0: # delete_item() returned an error
print("WARNING: There is nothing to delete.")
elif result == -1: # is_valid_index() returned False
print(f"WARNING: |{user_option}| is an invalid dish number!")
print("::: Would you like to delete another dish?", end=" ")
continue_action = input("Enter 'y' to continue.\n> ")
continue_action = continue_action.lower()
return restaurant_menu_list
Sample Program Flow
Deleting ALL dishes. Note that the user can only do this by selecting “A” (only the upper case “A”) and then by confirming with “Yes” (not “Y”, not “yes”, …)
::: Enter a menu option > D You selected option D to > Delete. Which dish would you like to delete? Press A to delete the entire menu for this restaurant, M to cancel this operation ------------------------------------------ 1. BURRITO 2. RICE BOWL 3. MARGHERITA ------------------------------------------ > A ::: WARNING! Are you sure you want to delete the entire menu ? ::: Type Yes to continue the deletion. > Yes Deleted the entire menu. ::: Press Enter to continueYou can check that every dish got deleted by next going to the main menu, and selecting “L”ist:
::: Enter a menu option > L You selected option L to > List. ::: What field would you like to list? A - complete menu V - vegetarian dishes only ::: Enter your selection > A You selected |A| to list |complete menu|. ------------------------------------------ ------------------------------------------ ::: Press Enter to continueDeleting one dish - example below shows what happens if the wrong dish ID is used, but then the user is given another chance to delete and they use the correct dish ID:
::: Enter a menu option > D You selected option D to > Delete. Which dish would you like to delete? Press A to delete the entire menu for this restaurant, M to cancel this operation ------------------------------------------ 1. BURRITO 2. RICE BOWL 3. MARGHERITA ------------------------------------------ > 4 WARNING: |4| is an invalid dish number! ::: Would you like to delete another dish? Enter 'y' to continue. > y Which dish would you like to delete? Press A to delete the entire menu for this restaurant, M to cancel this operation ------------------------------------------ 1. BURRITO 2. RICE BOWL 3. MARGHERITA ------------------------------------------ > 1 Success! Deleted the dish |burrito| ::: Would you like to delete another dish? Enter 'y' to continue. > n ::: Press Enter to continueNote that the user CAN keep choosing to enter ‘y’ at the “Would you like to delete another dish?…” prompt and be able to go back to the start of the delete menu choices. This would allow them to keep deleting dishs one by one.
Again, you can check that the dish example from above (burrito) got deleted by going to the main menu, and selecting “L”ist:
::: Enter a menu option > L You selected option L to > List. ::: What field would you like to list? A - complete menu V - vegetarian dishes only ::: Enter your selection > A You selected |A| to list |complete menu|. ------------------------------------------ 1. RICE BOWL * Calories: 400 * Price: 14.9 * Is it vegetarian: no * Spicy level: Hot 2. MARGHERITA * Calories: 800 * Price: 18.9 * Is it vegetarian: no * Spicy level: Low key spicy ------------------------------------------ ::: Press Enter to continueExample when nothing gets deleted (i.e. you already deleted every dish and now you select delete again).
::: Enter a menu option > D You selected option D to > Delete. WARNING: There is nothing to delete! ::: Press Enter to continue