RetroBBS - comp.lang.python - Re: Variable scope inside and outside functions - global statement being overridden by assignation unless preceded by reference

Re: Variable scope inside and outside functions - global statement being overridden by assignation unless preceded by reference

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From: grant.b.edwards@gmail.com (Grant Edwards)
Newsgroups: comp.lang.python
Subject: Re: Variable scope inside and outside functions - global statement
being overridden by assignation unless preceded by reference
Date: Wed, 6 Mar 2024 20:55:40 -0500 (EST)
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by: Grant Edwards - Thu, 7 Mar 2024 01:55 UTC

On 2024-03-07, dn via Python-list <python-list@python.org> wrote:

> The idea of importing a module into the REPL and then (repeatedly)
> manually entering the code to set-up and execute is unusual (surely type
> such into a script (once), and run that (repeatedly). As you say, most
> of us would be working from an IDE and hitting 'Run'. Am wondering why
> you weren't - but it's not important.

Unless the code is intended to be used as a module, 'import'ing it into
the REPL doesn't make sense.

A simple example:

---------------------------testit.py------------------------------
x = 'x'
y = 'y'
def foo():
global y
print("hi")
x = 'X'
y = 'Y'
print(x)
print(y)
------------------------------------------------------------------

The usual method to play with that interactively is

$ python -i testit.py
>>> x
'x'
>>> y
'y'
>>> foo()
hi
X
Y
>>> x
'x'
>>> y
'Y'
>>>

As we've seen, doing a 'from testit.py import *' doesn't let you test
what the OP was trying to test. Doing 'import testit.py' gets you
closer, but it's a hassle to test code that way. The right thing to do
is 'python -i <filename>' (or the equivalent button/option in an IDE).

https://docs.python.org/3/tutorial/interpreter.html

If you intended to use testit.py as a module, and wanted to experiment
with its behavior as a module, then go ahead and import it. But, don't
do 'from testit.py import *' until

1. you know how that differs from 'import testit.py'

and

2. you want to use that difference

Subject	Author
Re: Variable scope inside and outside functions - global statement being overrid	Grant Edwards

The universe is all a spin-off of the Big Bang.

devel / comp.lang.python / Re: Variable scope inside and outside functions - global statement being overridden by assignation unless preceded by reference