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

[fp2161 at gmail.com]

On Thursday, August 29, 2013 11:05:38 PM UTC+2, Chris Angelico wrote:
> On Fri, Aug 30, 2013 at 6:50 AM,  <fp2161 at gmail.com> wrote:
> 
> > My way is so obvious that it may not be that interesting...
> 
> >
> 
> > def func4(f1,f2,f3,f4):
> 
> >     def anon(x):
> 
> >         f1(f2(f3(f4(x))))
> 
> >     return anon
> 
> 
> 
> Or have it return the result of f1. And then, since it's an anonymous
> 
> function that simply returns an expression, I'd write it as:
> 
> 
> 
> def func4(f1,f2,f3,f4):
> 
>     return lambda x: f1(f2(f3(f4(x))))
> 
> 
> 
> Of course, that's still restricted to precisely four args. Extending
> 
> this concept to a variable number of arguments is, uhh, left as an
> 
> exercise to the reader. Which will probably end up going back to
> 
> reduce(). :)
> 
> 
> 
> ChrisA

Here is the generalisable version:


def comp(*func):
    def anon(x):
        res=x
        for f in func:
            res=f(res)
        return res
    return anon

you can then compose your function in __main__:
f4=comp(f5,f6,f7)
and call it:
print(x) ...

(I hope that Chris is happy now...)