Question

Take this example:

def f():
    myvar = None
    def g():
        print myvar

    ...
    myvar = get_real_value()
    g()

Is “myvar = None” a conventional (or at least, reasonable) way of declaring the variable, to make it visible to g()? Is there a better way? (Python 2.6.x, if relevant)

Answer 1

There is no need to declare the variable before the definition for g():

>>> def f():
...     def g():
...         print myvar
...     myvar = 1
...     g()
... 
>>> f()
1

However, if you can avoid referencing non-local variables in g() that would be preferable, which you would probably do here by having myvar be a parameter to g().