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"return" in def

Bruno Desthuilliers bruno.42.desthuilliers at websiteburo.invalid
Mon Dec 29 04:26:28 EST 2008 
John Machin a écrit :
> On Dec 29, 7:06 am, Roger <rdcol... at gmail.com> wrote:
>>> Curious. When I see a bare return, the first thing I think is that the
>>> author forgot to include the return value and that it's a bug.
>>> The second thing I think is that maybe the function is a generator, and
>>> so I look for a yield. If I don't see a yield, I go back to thinking
>>> they've left out the return value, and have to spend time trying to
>>> understand the function in order to determine whether that is the case or
>>> not.
>>> In other words, even though it is perfectly valid Python, bare returns
>>> always make the intent of the function less clear for me. I'm with Bruno
>>> -- if you have a function with early exits, and you need to make the
>>> intent of the function clear, explicitly return None. Otherwise, leave it
>>> out altogether.
>>> --
>>> Steven
>> To me this is the soundest argument.  Thanks for the advice.  I think
>> I'll follow this as a rule of thumb hereafter.
> 
> Please don't. Follow MRAB's advice, with the corollary that a
> generator is forced by the compiler to be a "procedure" in MRAB's
> terminology.

I fail to see any *practical* difference between MRAB's and Steven's 
POVs. In both cases, it boils down to
- don't use a bare return at the end of a def statement's body,
- either use only bare returns ('procedure') or explicitely return None 
('function')
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