[Tutor] a query

[Danny Yoo]

On 8 Aug 2002, Avinash Dutta wrote:

> is it possible to call a function B() which is defined inside another
> function A() from the scope of another function C() in python?

When we define an function inside another, we can treat it as if it were a
local variable --- it'll only be accessible from A().  So unless you
return that 'B' function from A(), we shouldn't be able to touch B.


> def A():
> ----def B():
>
> def x():
>
> def C():
> ----# how can i call B() from here.


This isn't possible directly, because 'B' is a local function of A, that
is, it's a local name as far as Python's concerned.

However, we can do something like this:

###
>>> def makeIncrementer(n):
...     def inc(x):
...         return x + n
...     return inc
...
>>> inc_by_one = makeIncrementer(1)
>>> inc_by_one(42)
43
>>> makeIncrementer("world")("hello")
'helloworld'
###

(I'm sorry about the last example; I just couldn't resist.  *grin*)


What are you trying to do with inner functions, though?  There may be a
more Pythonic way of approaching your problem.

Hope this helps!