Neil Cerutti a écrit :
> On 2007-01-24, Florian Lindner <[EMAIL PROTECTED]> wrote:
>
>>does python have static variables? I mean function-local
>>variables that keep their state between invocations of the
>>function.
>
>
> Yup. Here's a nice way. I don't how recent your Python must be
> to support this, though.
>
>
>>>>def foo(x):
>
> ... print foo.static_n, x
> ... foo.static_n += 1
> ...
>
>>>>foo.static_n = 0
Yup,I had forgotten this one. FWIW, it's an old trick.
There's also the closure solution:
def make_foo(start_at=0):
static = [start_at]
def foo(x):
print static[0], x
static[0] += 1
return foo
foo = make_foo()
And this let you share state between functions:
def make_counter(start_at=0, step=1):
count = [start_at]
def inc():
count[0] += step
return count[0]
def reset():
count[0] = [start_at]
return count[0]
def peek():
return count[0]
return inc, reset, peek
foo, bar, baaz = make_counter(42, -1)
print baaz()
for x in range(5):
print foo()
print bar()
print baaz()
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