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Re: Pipe in the "return" statement

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Billy Mays wrote:
> On 07/25/2011 10:16 AM, Archard Lias wrote:
>> On Jul 25, 2:03 pm, Ian Collins<ian-n...@hotmail.com>  wrote:
>>> On 07/26/11 12:00 AM, Archard Lias wrote:
>>>> Still I dont get how I am supposed to understand the pipe and its task/
>>>> idea/influece on control flow, of:
>>>> return<statement>    |<statement>
>>>> ??
>>>
>>> It's simply a bitwise OR.
>>
>> Yes, but how does it get determined, which one actually gets returned?
> 
> The return statement returns a single value from a function context. The 
> pipe operator takes 2 values and bitwise ORs* them together.  That 
> result is then returned to the caller.

Just for completeness, if the actual line had been

return <statement1> or <statement2>

then Python would compute <statement1>, and if its boolean value was 
True would return the computation of <statement1>, otherwise it would 
compute <statement2> and return that.  When 'or' is used, the first 
truthy* item is return, or the last falsey* item if none evaluate to True.

--> None or 2 or 0
2
--> None or 2 or 3
2
--> None or [] or 0
0

With 'and', the first falsey item is returned, unless all the items are 
   truthy in which case the last item is returned:

--> 2 and 3
3
--> 2 and 0 and 9
0

Hope this helps.

~Ethan~

* 'truthy' = bool(some expression or object) == True
* 'falsey' = bool(some expression or object) == False

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Pipe in the "return" statement Archard Lias <archardlias@googlemail.com> - 2011-07-25 05:00 -0700
  Re: Pipe in the "return" statement Ian Collins <ian-news@hotmail.com> - 2011-07-26 00:03 +1200
    Re: Pipe in the "return" statement Archard Lias <archardlias@googlemail.com> - 2011-07-25 07:16 -0700
      Re: Pipe in the "return" statement Billy Mays <81282ed9a88799d21e77957df2d84bd6514d9af6@myhashismyemail.com> - 2011-07-25 10:31 -0400
        Re: Pipe in the "return" statement Ethan Furman <ethan@stoneleaf.us> - 2011-07-25 13:07 -0700
          Re: Pipe in the "return" statement Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-07-28 08:26 +0200
      Re: Pipe in the "return" statement Oliver Bestwalter <oliver@bestwalter.de> - 2011-07-25 16:35 +0200
        Re: Pipe in the "return" statement Archard Lias <archardlias@googlemail.com> - 2011-07-25 08:05 -0700
      Re: Pipe in the "return" statement John Gordon <gordon@panix.com> - 2011-07-25 14:39 +0000
        Re: Pipe in the "return" statement Archard Lias <archardlias@googlemail.com> - 2011-07-25 08:06 -0700
      Re: Pipe in the "return" statement gwowen <gwowen@gmail.com> - 2011-07-25 07:42 -0700
  Re: Pipe in the "return" statement Christian Heimes <lists@cheimes.de> - 2011-07-25 14:33 +0200
    Re: Pipe in the "return" statement Archard Lias <archardlias@googlemail.com> - 2011-07-25 08:28 -0700
      Re: Pipe in the "return" statement Christian Heimes <lists@cheimes.de> - 2011-07-25 18:11 +0200
        Re: Pipe in the "return" statement Archard Lias <archardlias@googlemail.com> - 2011-07-25 09:30 -0700
  Re: Pipe in the "return" statement TonyO <guinness.tony@gmail.com> - 2011-07-25 05:52 -0700
    Re: Pipe in the "return" statement gwowen <gwowen@gmail.com> - 2011-07-25 06:00 -0700
    Re: Pipe in the "return" statement red floyd <redfloyd@gmail.com> - 2011-07-25 14:04 -0700
      reading  zipfile; problem using raw buffer "Sells, Fred" <fred.sells@adventistcare.org> - 2011-07-26 08:42 -0400
        Re: reading  zipfile; problem using raw buffer Billy Mays <81282ed9a88799d21e77957df2d84bd6514d9af6@myhashismyemail.com> - 2011-07-26 08:49 -0400
      Re: reading  zipfile; problem using raw buffer Peter Otten <__peter__@web.de> - 2011-07-26 15:04 +0200
      RE: reading  zipfile; problem using raw buffer "Sells, Fred" <fred.sells@adventistcare.org> - 2011-07-26 11:22 -0400

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