How do I use a while loop in python?

saolasosme

Also see: python help - while statement.

Demo code.

counter = 1
while counter <= 5:
    print(counter)
    counter = counter + 1
print("I can count")```

The result is.

$ python main.py
1
2
3
4
5
I can count

Here's a lot more useful while code example. Note that the correct_value would normally be extracted from a database of some type and not hard coded.

The demo code combines the while loop with if conditions.

correct_value = 3471
attempts = 0
max_attempts = 3

while attempts < max_attempts:
    passcode = int(input('Enter the correct value to proceed:'))
    attempts += 1
    attempts_left = max_attempts - attempts
    if passcode == correct_value:
        print("Great, Access Permitted!")
        break
    else: 
        print(f"Please try again, you have {attempts_left} attempts left")
else:
    print(f"Maximum attempts exceeded.")

Example execution of the code.

$ python main.py
Enter the correct value to proceed:
2345
Please try again, you have 2 attempts left
Enter the correct value to proceed:
6554
Please try again, you have 1 attempts left
Enter the correct value to proceed:
3471
Great, Access Permitted!

If the correct value was not entered. The else statement will be displayed:

$ python main.py
Enter the correct value to proceed:
5678
Please try again, you have 2 attempts left
Enter the correct value to proceed:
1234
Please try again, you have 1 attempts left
Enter the correct value to proceed:
6345
Please try again, you have 0 attempts left
Maximum attempts exceeded.