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Date: Wed, 28 Aug 2013 08:11:34 -0500
From: Tim Chase <python.list@tim.thechases.com>
To: AdamKal <adamkalinski@gmail.com>
Subject: 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