TheSaint a écrit :
On 04:51, giovedì 12 giugno 2008 Terry Reedy wrote:
First of all a big thank you, all.
def makeappender():
data = ['','']
def appender(val):
<code that mutates data>
return appender
I'll give it a try. I just doubting if the data will be shared outside the
function.
Each time makeappender is called, it returns a new appender function
object with it's own 'data' object. So 'data' won't be shared between
different instances of the appender function.
Actually, my practice goes to send all variables to the functions and
expecting a returned value.
Mostly a sane, sound and sensible approach IMHO - but doesn't work that
well when the function needs to maintain own state between calls.
Usually I'm not relying on that module's
variables are read inside a function. Probably I got wrong learning or
experiences.
As long as you only *read* module's globals from within a function,
that's mostly ok. When you start *writing* them it may be time to
reconsider the design (not that it's necessarily bad, but it's a
possible signal that something is wrong).
For multiple functions, use classes.
Well... Closures are poor men's objects, or so they say (or is that the
other way round ?-).
def make_person(name, age):
state = dict(name=name, age=age)
def set_name(new_name=None):
state['name'] = new_name
def get_name():
return state['name']
def grow():
state['age'] += 1
def get_age()
return state['age']
return set_name, get_name, grow, get_age
(toto_set_name,
toto_get_name,
toto_grow,
toto_get_age) = make_person('toto', 42)
A bit cumbersome, indeed !-)
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