Is it ok to skip "return None"?

Question

I wonder if it is bad manner to skip return None, when it is not needed.

Example:

def foo1(x):     if [some condition]:         return Baz(x)     else:         return None  def foo2(x):     if [some condition]:         return Baz(x)  bar1 = foo1(x) bar2 = foo2(x) 

In both cases, when condition is false, function will return with None.

Answer 1

Like you said, return None is (almost) never needed.

But you should consider that the intention of your code is much clearer with an explicit return None. Remember: a piece of code also needs to be readable by human-beings, and being explicit usually helps.

Answer 2

To expound on what others have said, I use a return None if the function is supposed to return a value. In Python, all functions return a value, but often we write functions that only ever return None, because their return value is ignored. In some languages, these would be called procedures.

So if a function is supposed to return a value, then I make sure all code paths have a return, and that the return has a value, even if it is None.

If a function "doesn't" return a value, that is, if it is never called by someone using its return value, then it's ok to end without a return, and if I need to return early, I use the bare form, return.