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]

Subhash Chandra wrote:

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 ---

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]

Subhash Chandra <no**************@yahoo.com> writes:

How can I make counter variable in function foo reference to global
counter variable in the following code.
add the line " global counter" just after "def foo():"
Generally C programmers tend to write code like that I am looking
for simple way to do it in python.
Generally C programmers do horrible things. Please consider whether
you really, really should be emulating C style in Python.
--- BEGIN ---
counter = 0

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

foo()
--- END ---

[Miki Tebeka]

Hello Subhash,

--- BEGIN ---
counter = 0

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

foo()
--- END ---

Today we have generators:

def foo(): for count in range(10):
print "count = ", count
yield count
count += 1 gen = foo()
gen.next() count = 0
0 gen.next() count = 1
1

HTH.
Miki