Python list while loop check

Question

my aim is to run the while loop until the user inputs a option that is in my list. If they do the while loop should end.

exchangeCurrency = input("what currency would you like to convert to: ").upper()

myList = ["USD", "ERU", "BRL", "JPY", "TRY"]

while exchangeCurrency != myList:
    print("this is not a valid inpit")
    continue
else:
    break

Does this answer your question? [Check if something is (not) in a list in Python](https://stackoverflow.com/questions/10406130/check-if-something-is-not-in-a-list-in-python) — Ignatius Reilly, Oct 18 '22 at 22:23

score 3 · Accepted Answer · answered Oct 18 '22 at 22:20

3

while True:
    exchangeCurrency = input("what currency would you like to convert to: ").upper()
    if exchangeCurrency in myList:
        break

answered Oct 18 '22 at 22:20

logan_9997

574
2
14

score 1 · Answer 2 · answered Oct 18 '22 at 22:20

1

This would be the code:

myList = ["USD", "ERU", "BRL", "JPY", "TRY"]

userInput = input("Enter a currency: ").upper()
while userInput not in myList:
    print("Currency not found")
    userInput = input("Enter a currency: ").upper()

answered Oct 18 '22 at 22:20

Flow

846
9
24

Can save two lines with an assignment expression: `while (userInput := input("Enter a currency: ").upper()) not in myList:` – flakes Oct 18 '22 at 22:21
@flakes I do know this is a valid option but it is usually better to not give a one-linear to a beginner. – Flow Oct 18 '22 at 22:23

score 0 · Answer 3 · answered Oct 18 '22 at 22:22

0

myList = ["USD", "ERU", "BRL", "JPY", "TRY"]
while (exchangeCurrency := input("what currency would you like to convert to: ").upper()) not in myList:
    print("Error: currency not found")

answered Oct 18 '22 at 22:22

Mohamed Darwesh

659
4
17

score -1 · Answer 4 · answered Oct 18 '22 at 22:19

-1

a simple solution that may work

isTrue = True

while isTrue:
 if exchangeCurrency != myList:
   print("try again. Invalid currency")
 else:
   print("this currency is on the list")
   isTrue = False

answered Oct 18 '22 at 22:19

Squid

27
9

Python list while loop check

4 Answers4