[Tutor] variables question.

[Alan Gauld]

"Jeff Honey" <jeffh at pona.net> wrote

> I have a question about where variables are exposed in python.

Take a look at the namespaces topic in my tutor for more details 
but...

> I have a monolothic script with a number of functions defined,
> can those functions share variables?

Yes but its usually bad practice.
Python considers module level variables to be "global".
global vars can be read inside a functon within the same module.
global vars can be changed inside a function in the same module 
provided they are declared as global within the function:

foo = 42

def f():
  global foo   # use the global var
  foo = 66
  return foo

print foo
print f()
print foo

> can I instantiate them outside the function of where they are 
> needed?

Yes, see foo above

> do they need to be wrapped in quotes, ever? For example:
>
> blah = 123

blah refers to an integer

> foo = 'somestring'

foo refers to a string. literal strings need quotes

bar = raw_uinput('?')    # bar refers to a strintg input by the user

> def function(foo):
>     code that needs foo
>     anotherfunction(blah)

No problem

> def anotherfunction(blah):
>     code that needs blah
>     code that uses foo

This needs a global foo line added at the top.

> def function(blah, foo):
>     anotherfunc(blah)
>     anotherfunc(foo)

No problem. blah and foo are local variables inside function().
They are passed as arguments to anotherfunc() whioch weill
assign the objects to their parameters and treat as local
variables within anotherfunc()

> ..what about my python being called from some parent script
> (something OTHER than python)

Thats possible but trickier

> that instantiates blah and foo FOR me?

As is this.

But bopth are easier if its another Python script.

> Can I just plug those into my code like I would normally?

No.

> I guess this is more about HOW and WHERE I can
> make variables available for use.

See my tutorial topic...


-- 
Alan Gauld
Author of the Learn to Program web site
http://www.alan-g.me.uk/