Scope question

[Subhash Chandra]

Hi,

How can I make counter variable in function foo reference to global counter
variable in the following code. Generally C programmers tend to write code like
that I am looking for simple way to do it in python.

--- BEGIN ---
counter = 0

def foo():
if counter < 10:
print "count = ", counter
counter += 1

foo()
--- END ---

regards,
Subhash
--
Remove "nospam_" for direct reply

[Gandalf]

Re: Scope question

Subhash Chandra wrote:
[color=blue]
> Hi,
>
> How can I make counter variable in function foo reference to global
> counter variable in the following code. Generally C programmers tend
> to write code like that I am looking for simple way to do it in python.
>
> --- BEGIN ---
> counter = 0
>
> def foo():
> if counter < 10:
> print "count = ", counter
> counter += 1
>
> foo()
> --- END ---[/color]

You need to tell explicitly that the name 'counter' is global. It is
because used this statment in your function:

counter += 1

which is a rebind of the name 'counter'. So python thinks it must be a
local name.
Here is what you want:

counter = 0

def foo():
global counter
if counter < 10:
print "count = ", counter
counter += 1

foo()

[Jacek Generowicz]

Re: Scope question

Subhash Chandra <nospam_yschand ra@yahoo.com> writes:
[color=blue]
> How can I make counter variable in function foo reference to global
> counter variable in the following code.[/color]

add the line " global counter" just after "def foo():"
[color=blue]
> Generally C programmers tend to write code like that I am looking
> for simple way to do it in python.[/color]

Generally C programmers do horrible things. Please consider whether
you really, really should be emulating C style in Python.
[color=blue]
> --- BEGIN ---
> counter = 0
>
> def foo():
> if counter < 10:
> print "count = ", counter
> counter += 1
>
> foo()
> --- END ---[/color]

[Miki Tebeka]

Re: Scope question

Hello Subhash,
[color=blue]
> --- BEGIN ---
> counter = 0
>
> def foo():
> if counter < 10:
> print "count = ", counter
> counter += 1
>
> foo()
> --- END ---[/color]
Today we have generators:[color=blue][color=green][color=darkred]
>>> def foo():[/color][/color][/color]
for count in range(10):
print "count = ", count
yield count
count += 1[color=blue][color=green][color=darkred]
>>> gen = foo()
>>> gen.next()[/color][/color][/color]
count = 0
0[color=blue][color=green][color=darkred]
>>> gen.next()[/color][/color][/color]
count = 1
1[color=blue][color=green][color=darkred]
>>>[/color][/color][/color]

HTH.
Miki