[Visualpython-users] Re: Python/C++

[Scott D. D. <Sco...@Ac...>]

John Brawley wrote:
> I realize this is not the list for this question, but some of you might
> know, and I'm not currently on the Python list....
> 
> Can anyone tell me how Python implements C++ in the case of _tuples_?
This question makes no sense.

> I'm assuming Python is built somewhat on C (or C++), and in C++ you can't
> return more than one item from a function, but Python allows one to return
> as many (up to 10?) variables as one wants (this is one reason Python is so
> "powerful"; returning three variables at once makes it a 'natural' for 3D
> space work with lots and lots of x,y,z dealings).

Python functions only ever return a single value, but that value might
be a tuple of values.  There is no limit of 10 (or so) values in that
tuple.  Consider:

     def powers(a):
         return (1, a, a**2, a**3, a**4, a**5, a**6, a**7, a**8, a**9,
                 a**10, a**11, a**12, a**13)

     a,b,c,d,e,f,g,h,i,j,k,l,m,n = powers(1.2)

Or even:

     def pows(a, number):
         return [a ** n for n in range(number)]

     a,b,c,d = pows(1.2, 4)

     a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z = pows(1.1, 26)

Modern C (and C++) similarly allow you to return a struct.

Take a python function that you think produces multiple results, and
simply print the result of that function.  It is a single item which
is "dis-assembled" in the python assignment.  For example, you can do
the following:

     (a, b), (c, d, e) = [(1, 3), [1.1, 2.3, 'f']]


-- 
-- Scott David Daniels
Sco...@Ac...