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Re: Is there a function that applies list of functions to a value?

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On 2013-08-28 05:52, AdamKal wrote:
> From time to time I have to apply a series of functions to a value
> in such a way:
> 
> func4(func3(func2(func1(myval))))
> 
> I was wondering if there is a function in standard library that
> would take a list of functions and a initial value and do the above
> like this:
> 
> func_im_looking_for([func1, func2, func3, func4], myval)

At least in Py2.x you can use reduce:

  reduce(lambda value, fn: fn(value), [list_of_functions], myval)

I believe it was moved into functools.reduce() in Py3.x meaning you
might want to do something like

  try:
    reduce # see if it's already in __builtins__
  except NameError: # running Py3...
    from functools import reduce

or

  try:
    from functools import reduce
  except ImportError:
    pass  # it should already be in __builtins__ for pre-2.6

at the top to make sure it's in your global namespace.

-tkc

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Is there a function that applies list of functions to a value? AdamKal <adamkalinski@gmail.com> - 2013-08-28 05:52 -0700
  Re: Is there a function that applies list of functions to a value? Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-08-28 16:10 +0300
    Re: Is there a function that applies list of functions to a value? fp2161@gmail.com - 2013-08-29 15:48 -0700
  Re: Is there a function that applies list of functions to a value? Tim Chase <python.list@tim.thechases.com> - 2013-08-28 08:11 -0500
    Re: Is there a function that applies list of functions to a value? Jussi Piitulainen <jpiitula@ling.helsinki.fi> - 2013-08-28 16:19 +0300
    Re: Is there a function that applies list of functions to a value? AdamKal <adamkalinski@gmail.com> - 2013-08-28 06:23 -0700
      Re: Is there a function that applies list of functions to a value? Chris Angelico <rosuav@gmail.com> - 2013-08-28 23:26 +1000
      Re: Is there a function that applies list of functions to a value? Tim Chase <python.list@tim.thechases.com> - 2013-08-28 08:43 -0500
        Re: Is there a function that applies list of functions to a value? AdamKal <adamkalinski@gmail.com> - 2013-08-28 06:50 -0700
  Re: Is there a function that applies list of functions to a value? ishish <ishish@domhain.de> - 2013-08-28 14:17 +0100
  Re: Is there a function that applies list of functions to a value? Thomas Rachel <nutznetz-0c1b6768-bfa9-48d5-a470-7603bd3aa915@spamschutz.glglgl.de> - 2013-08-28 15:09 +0200
  Re: Is there a function that applies list of functions to a value? Josh English <Joshua.R.English@gmail.com> - 2013-08-28 11:50 -0700
    Re: Is there a function that applies list of functions to a value? fp2161@gmail.com - 2013-08-29 23:17 -0700
      Re: Is there a function that applies list of functions to a value? alex23 <wuwei23@gmail.com> - 2013-08-30 16:36 +1000
        Re: Is there a function that applies list of functions to a value? Fabrice Pombet <fp2161@gmail.com> - 2013-08-30 01:11 -0700
  Re: Is there a function that applies list of functions to a value? fp2161@gmail.com - 2013-08-29 13:50 -0700
    Re: Is there a function that applies list of functions to a value? Chris Angelico <rosuav@gmail.com> - 2013-08-30 07:05 +1000
      Re: Is there a function that applies list of functions to a value? fp2161@gmail.com - 2013-08-29 14:27 -0700
        Re: Is there a function that applies list of functions to a value? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-08-30 02:18 +0000
        Re: Is there a function that applies list of functions to a value? Chris Angelico <rosuav@gmail.com> - 2013-08-30 07:35 +1000
          Re: Is there a function that applies list of functions to a value? fp2161@gmail.com - 2013-08-29 23:14 -0700
            Re: Is there a function that applies list of functions to a value? alex23 <wuwei23@gmail.com> - 2013-08-30 16:23 +1000
              Re: Is there a function that applies list of functions to a value? Fabrice Pombet <fp2161@gmail.com> - 2013-08-30 01:06 -0700
      Re: Is there a function that applies list of functions to a value? fp2161@gmail.com - 2013-08-29 14:48 -0700
        Re: Is there a function that applies list of functions to a value? Terry Reedy <tjreedy@udel.edu> - 2013-08-30 00:38 -0400
    Re: Is there a function that applies list of functions to a value? Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-08-30 02:09 +0000
      Re: Is there a function that applies list of functions to a value? fp2161@gmail.com - 2013-08-29 23:06 -0700

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