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Re: from future import pass_function

References <d1o4e9-tlr.ln1@satorlaser.homedns.org>
Date 2012-07-26 02:05 +1000
Subject Re: from future import pass_function
From Chris Angelico <rosuav@gmail.com>
Newsgroups comp.lang.python
Message-ID <mailman.2575.1343232342.4697.python-list@python.org> (permalink)

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On Wed, Jul 25, 2012 at 6:40 PM, Ulrich Eckhardt
<ulrich.eckhardt@dominolaser.com> wrote:
> I just had an idea, it occurred to me that the pass statement is pretty
> similar to the print statement, and similarly to the print() function, there
> could be a pass() function that does and returns nothing.
>
> Example:
>    def pass():
>        return
>
>    try:
>        do_something()
>    except:
>        pass()

Except that "pass" is a syntactic construct that basically says "hey,
I have an indented block here, but there's no code in it". It's not
executable any more than the syntactic token "INDENT" is. It's more
closely related to the colon at the end of "try" than it is to the
"do_something()" call.

By comparison, Python 2's print statement is executable. It causes
real action to happen at run-time. It makes sense to pass "print" as
an argument to something; for instance:

def some_generator():
   yield blah

map(print,some_generator())

Simple way of making the iterator display its yielded result. I cannot
imagine any circumstance in which you'd want to map "pass" over
everything. But then, as Teresa said, I'm only one, and possibly I'm
wrong!

ChrisA

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Thread

from future import pass_function Ulrich Eckhardt <ulrich.eckhardt@dominolaser.com> - 2012-07-25 10:40 +0200
  Re: from future import pass_function Philipp Hagemeister <phihag@phihag.de> - 2012-07-25 12:30 +0200
  Re: from future import pass_function Nicholas Cole <nicholas.cole@gmail.com> - 2012-07-25 11:33 +0100
  Re: from future import pass_function Devin Jeanpierre <jeanpierreda@gmail.com> - 2012-07-25 07:02 -0400
  Re: from future import pass_function Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-25 11:33 +0000
    Re: from future import pass_function Ross Ridge <rridge@csclub.uwaterloo.ca> - 2012-07-25 21:42 -0400
      Re: from future import pass_function Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-26 02:38 +0000
        Re: from future import pass_function Ross Ridge <rridge@csclub.uwaterloo.ca> - 2012-07-25 23:30 -0400
          Re: from future import pass_function Chris Angelico <rosuav@gmail.com> - 2012-07-26 13:53 +1000
            Re: from future import pass_function Ross Ridge <rridge@csclub.uwaterloo.ca> - 2012-07-26 00:03 -0400
              Re: from future import pass_function Ethan Furman <ethan@stoneleaf.us> - 2012-07-25 21:32 -0700
                Re: from future import pass_function John Ladasky <john_ladasky@sbcglobal.net> - 2012-07-26 13:55 -0700
                Re: from future import pass_function Ethan Furman <ethan@stoneleaf.us> - 2012-07-26 14:23 -0700
                Re: from future import pass_function John Ladasky <john_ladasky@sbcglobal.net> - 2012-07-26 15:20 -0700
                Re: from future import pass_function John Ladasky <john_ladasky@sbcglobal.net> - 2012-07-26 15:20 -0700
                Re: from future import pass_function John Ladasky <john_ladasky@sbcglobal.net> - 2012-07-26 13:55 -0700
              Re: from future import pass_function Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-07-26 08:43 +0100
          Re: from future import pass_function alex23 <wuwei23@gmail.com> - 2012-07-25 21:20 -0700
        Re: from future import pass_function Rusi <rustompmody@gmail.com> - 2012-07-25 22:09 -0700
        Re: from future import pass_function Ulrich Eckhardt <ulrich.eckhardt@dominolaser.com> - 2012-07-26 08:59 +0200
          Re: from future import pass_function Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-26 09:26 +0000
            Re: from future import pass_function Ulrich Eckhardt <ulrich.eckhardt@dominolaser.com> - 2012-07-26 13:45 +0200
              Re: from future import pass_function Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-26 15:21 +0000
                Re: from future import pass_function Joel Goldstick <joel.goldstick@gmail.com> - 2012-07-26 12:55 -0400
                RE: from future import pass_function "Prasad, Ramit" <ramit.prasad@jpmorgan.com> - 2012-07-26 17:19 +0000
                Re: from future import pass_function Chris Angelico <rosuav@gmail.com> - 2012-07-27 03:33 +1000
                Re: from future import pass_function Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-07-27 00:25 +0100
                Re: from future import pass_function Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-07-27 00:23 +0100
      Re: from future import pass_function alex23 <wuwei23@gmail.com> - 2012-07-25 21:17 -0700
  Re: from future import pass_function Chris Angelico <rosuav@gmail.com> - 2012-07-26 02:05 +1000
    Re: from future import pass_function Ulrich Eckhardt <ulrich.eckhardt@dominolaser.com> - 2012-07-26 08:39 +0200
      Re: from future import pass_function Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2012-07-26 08:36 +0000
      Re: from future import pass_function Terry Reedy <tjreedy@udel.edu> - 2012-07-26 10:38 -0400
  Re: from future import pass_function Ethan Furman <ethan@stoneleaf.us> - 2012-07-25 09:28 -0700
  Re: from future import pass_function Devin Jeanpierre <jeanpierreda@gmail.com> - 2012-07-25 12:48 -0400
  Re: from future import pass_function Devin Jeanpierre <jeanpierreda@gmail.com> - 2012-07-25 14:17 -0400
  Re: from future import pass_function Michael Hrivnak <mhrivnak@hrivnak.org> - 2012-07-26 01:20 -0400
    Re: from future import pass_function Ulrich Eckhardt <ulrich.eckhardt@dominolaser.com> - 2012-07-26 08:42 +0200
      Re: from future import pass_function Michael Hrivnak <mhrivnak@hrivnak.org> - 2012-07-26 17:15 -0400
  Re: from future import pass_function Mark Lawrence <breamoreboy@yahoo.co.uk> - 2012-07-26 08:50 +0100
    Re: from future import pass_function Ulrich Eckhardt <ulrich.eckhardt@dominolaser.com> - 2012-07-27 08:39 +0200
  Re: from future import pass_function Devin Jeanpierre <jeanpierreda@gmail.com> - 2012-07-26 05:16 -0400
  Re: from future import pass_function Chris Angelico <rosuav@gmail.com> - 2012-07-26 19:42 +1000
  Re: from future import pass_function Devin Jeanpierre <jeanpierreda@gmail.com> - 2012-07-26 06:00 -0400
  Re: from future import pass_function rusi <rustompmody@gmail.com> - 2012-07-26 08:01 -0700
  Re: from future import pass_function Dennis Lee Bieber <wlfraed@ix.netcom.com> - 2012-07-26 14:01 -0400
  Re: from future import pass_function Chris Angelico <rosuav@gmail.com> - 2012-07-27 04:14 +1000
  Re: from future import pass_function John Ladasky <john_ladasky@sbcglobal.net> - 2012-07-26 13:48 -0700
    Re: from future import pass_function Ian Kelly <ian.g.kelly@gmail.com> - 2012-07-26 15:18 -0600
    Re: from future import pass_function Ethan Furman <ethan@stoneleaf.us> - 2012-07-26 15:35 -0700
    Re: from future import pass_function Terry Reedy <tjreedy@udel.edu> - 2012-07-27 00:21 -0400
  Re: from future import pass_function Michael Hrivnak <mhrivnak@hrivnak.org> - 2012-07-26 17:20 -0400

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