[Tutor] Recursive assignment in nested lists

[Asokan Pichai]

On Sat, Aug 4, 2012 at 12:28 PM, Alonzo Quijote
<alonzo.quijote at gmail.com> wrote:
> Is there a way to define a function which takes
>    a list (of lists),
>    a position specified by a list of integers [i0,i1,...,in], and
>    a value
> and returns the result of setting
>     list[i0][i1]...[in]=value
>
> The following function works for positions up to length 3 only.
> Is it possible to write a general function that does this?
>
> def setValueAtPosition(list,pos,value):
>     if len(pos)==1:
>         list[pos[0]]=value
>     elif len(pos)==2:
>         list[pos[0]][pos[1]]=value
>     elif len(pos)==3:
>         list[pos[0]][pos[1]][pos[2]]=value
>     return list
>
> For example
>>>> aa=[1,2,[3,4]]
>
>>>> setValueAtPosition(aa,[2,0],5)
> [1, 2, [5, 4]]
>
>>>> aa
> [1, 2, [5, 4]]
>
> _______________________________________________

Seems very odd requirement. Anyway here is one way:
---------------

def setValue(NestedList, pos, value):
      nl = NestedList
      for p in pos[:-1]:
           nl = nl[p]
      nl[pos[-1]] = value
      return NestedList
-------------------------
Asokan Pichai

If a language is designed for non-programmers, soon only
non-programs get written in it.                 --- Anonymouse