[Tutor] Return T/F vs print T/F

[Sivaram Neelakantan]

On Sat, Feb 04 2012,bob gailer wrote:

> On 2/4/2012 9:38 AM, Sivaram Neelakantan wrote:
>> While trying out code, I have trouble following the difference between
>>
>> return True vs print True and the same with False.  If I use return
>> for the True/False statements, nothing gets printed.  Why?
>
> Why did you expect something to be printed?

err...return sends something back as in True or False?


>
> Perhaps you are confused between what happens in the interactive
> window vs running a program?

Possibly.  But I was coding in an Emacs buffer and sending it to the
python subprocess from within Emacs.  Does that have anything to do
with it?

>
> Python 2.6.5 (r265:79096, Mar 19 2010, 21:48:26) [MSC v.1500 32 bit
> (Intel)] on win32
> Type "help", "copyright", "credits" or "license" for more information.
>>>> def f():
> ...   return True
> ...
>>>> f()
> True
>>>> def g():
> ...     print True
> ...
>>>> g()
> True
>>>> print f()
> True
>>>> print g()
> True
> None
>
> In the interactive window, when you call a function, Python displays
> the returned value.  When you run a program with a call to a
> function, Python does NOT display the returned value.
>
> A function that does not execute a return will return None; in the
> interactive window nothing is displayed.
>
> Is that sufficient?

Right, thanks for this, will check this thing out again.

 sivaram
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