Is there a way to return literally nothing in python?

Question

I'm learning python and I was just wondering if I there was a way to write a code that does something like:

def f(x):
    if x>1:
       return(x)
    else:
        # don't return anything

I'm asking about the else part of the code. I need to not return anything if x<=1, returning None isn't acceptable.

Answer 1

There is no such thing as "returning nothing" in Python. Every function returns some value (unless it raises an exception). If no explicit return statement is used, Python treats it as returning None.

So, you need to think about what is most appropriate for your function. Either you should return None (or some other sentinel value) and add appropriate logic to your calling code to detect this, or you should raise an exception (which the calling code can catch, if it wants to).

Answer 2

To literally return 'nothing' use pass, which basically returns the value None if put in a function(Functions must return a value, so why not 'nothing'). You can do this explicitly and return None yourself though.

So either:

if x>1:
    return(x)
else:
    pass

or

if x>1:
    return(x)
else:
    return None

will do the trick.

Answer 3

There's nothing like returning nothing but what you are trying to do can be done by using an empty return statement. It returns a None.

You can see an example below:

if 'account' in command:
    account()

def account():
    talkToMe('We need to verify your identity for this. Please cooperate.')
    talkToMe('May I know your account number please?')
    acc_number = myCommand()
    talkToMe('you said your account number is '+acc_number+'. Is it right?')
    confirmation = myCommand()
    if confirmation!='yes' or 'correct' or 'yeah':
        talkToMe('Let\'s try again!')
        account()
    else:
        talkToMe('please wait!')
    return

This will return nothing to calling function but will stop the execution and reach to the calling function.

Answer 4

How about this?

def function(x):
     try:
         x = x+1
         return (x)
     except:
         return ('')