If inside while loop

Question

again = True

while(again == True):

    yn = input("Do you want to do it again? (y or n)").lower()

    if(yn == 'y' or 'yes'):
        again == True
    elif(yn == 'n' or 'no):
        again == False

How do I make this code work? When I run it, it will always come out to be true.. =/

Answer 1

Let's start from the beginning:

while(again == True):

1. You don't need the parentheses here

2. You don't need the == True bit. again is suffice as it will have a boolean value of True.

if(yn == 'y' or 'yes'):

1. Once again, parenthesis aren't needed.

2. That line of code is translated as if (yn == 'y') or ('yes'):. This will always be true as 'yes' is considered True (not an empty string)

3. In python, you need to do if yn == 'y' or yn == 'yes':

4. Or you can do if yn in ('y', 'yes')

again == True

1. == is for comparisons. = is for assignments

2. This occurs in your else block.

Answer 2

In the final 4 lines of your program you aren't assigning again to have the value true, you are checking if again equals True/False.

== is completely different from =.

Answer 3

This won't work:

if (yn == 'y' or 'yes'):
    # ...
elif(yn == 'n' or 'no):

The correct way is:

if yn in ('y' or 'yes'):
    # ...
elif yn in ('n' or 'no):

Also, inside the conditions the assignments are wrong, use a single =. They should look like this:

again = True
# ...
again = False

Answer 4

You are mistaking the equality operator == with the assignment operator =. Also the statement yn == 'y' or 'yes' is buggy, since the right hand side is a non-empty string, which evaluates to True in a boolean context.

Declaring a variable simply to handle loop termination is not pythonic. I would rewrite your code entirely to be:

while True:
    yn = input("Do you want to do it again? (y or n)").lower()
    if yn in ('n','no'):
        break

Answer 5

if(yn == 'y' or 'yes'): # ----

The value of above statement is always true independent of valu of “yn” because right side of “or” is always true in your case. so it will never execute else part. So to avoid this, You have to compare value of “yn” with each possibility. one of the simple way is that

if(yn == 'y' or yn == 'yes'):
    again == True
elif(yn == 'n' or yn == 'no):
    again == False

Answer 6

your if else statment should be

if xxx: again = True elif yyy: again = False

Note difference between = and ==.