为一个循环中的多个输入创建一个元音变量

Question

I'm trying to create a variable within a loop that will print "an" in a response if the first letter of that response is a vowel. Here's my script:

responses = {}

polling_active = True

while polling_active:
    name = input("\nWhat is your name? ")
    response = input("Which kind of sandwich do you want? ")

    if response[0] in ('a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U'):
        a_an = "an"
    else:
        a_an = "a"

    responses[name] = response

    repeat = input("Would you like to let another person order? (yes/no) ")
    if repeat == 'no':
        polling_active = False

print("\n-- Order --")
for name, response in responses.items():
    print(name + " would like " + a_an + " " + response + " sandwich.")

Here's the output. When just one order is taken, the variable works, but when multiple orders are taken, the a_an variable remains the same.

Python ❯ python3 sandwich_orders.py                                                  ⏎

What is your name? Alex
Which kind of sandwich do you want? egg
Would you like to let another person order? (yes/no) no

-- Order --
Alex would like an egg sandwich.
Python ❯ python3 sandwich_orders.py

What is your name? Alex
Which kind of sandwich do you want? ham
Would you like to let another person order? (yes/no) no

-- Order --
Alex would like a ham sandwich.
Python ❯ python3 sandwich_orders.py

What is your name? Alex
Which kind of sandwich do you want? egg
Would you like to let another person order? (yes/no) yes

What is your name? Steve
Which kind of sandwich do you want? ham
Would you like to let another person order? (yes/no) no

-- Order --
Alex would like a egg sandwich.
Steve would like a ham sandwich.

Answer 1

The issue is that you are not saving the separator (a, an) for each iteration. My solution saves the value within the pre-existing dictionary for use later!

if response[0].lower() in ('a', 'e', 'i', 'o', 'u'):#we can also convert to lowercase and check a modified list. Just to shorten, not necessary
        a_an = "an"
    else:
        a_an = "a"

    responses[name] = [a_an, response] #modify dict to contain [delimiter, response]

#... other code here

for name, response in responses.items():
    print(name + " would like " + response[0] + " " + response[1] + " sandwich.")
    #where response[0] is our delimiter and response[1] is our type

Answer 2

Welcome to programming! You are almost there. Move the

 if response[0] in ('a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U'): a_an = "an" else: a_an = "a" 

Inside the for loop before the print.

Answer 3

The problem is that you overwrite your a_an variable each time you make an additional order. You need to save it instead for each order in a batch. One way to do it is to simply concatenate it within the while loop with the response,

responses[name] = a_an + ' ' + response 

With this fix the rest of your program remains the same except:

for name, response in responses.items():
    print(name + " would like " + response + " sandwich.")

Answer 4

You are going to need another list to store the different values of a_an for the different responses. If not, it just takes the value of the last response.

Answer 5

I created a little procedure to fix your problem.

name = 'Alex'
#storing the sandwiches types
#new values: types.append('value')
types = ['ham','egg']

for i in range(0,len(types)):

    response = types[i]

    if response[0] in ('a', 'e', 'i', 'o', 'u', 'A', 'E', 'I', 'O', 'U'):
        a_an = "an"
    else:
        a_an = "a"

    print(name + " would like " + a_an + " " + response + " sandwich.")

It's important to keep your evaluation list inside the for loop. Because of the len(types) it will evaluate the expression dinamically for all the elements in the list.