Question

I often find myself writing if / elif / else constructs in python, and I want to include options which can occur, but for which the corresponding action is to do nothing. I realise I could just exclude those if statements, but for readability I find it helps to include them all, so that if you are looking through the code you can see what happens as a result of each option. How do I code the no-op? Currently, I’m doing it like this:

no_op = 0  if x == 0:     y = 2 * a elif x == 1:     z = 3 * b elif x == 3:     no_op 

(The code is actually quite a bit longer than that, and more complicated. This is just to illustrate the structure).

I don’t like using a variable as a no-op, but it’s the neatest way I could think of. Is there a better way?

Answer 1

Use pass for no-op:

if x == 0:   pass else:   print 'x not equal 0' 

And here’s another example:

def f():   pass 

Or:

class c:   pass