Question about import and namespace

[jdemoor]

Hi,

I'm new to Python and have the following problem :
I have an application started by a main.py file, which does a ' from
module_1 import * '.
main.py is responsible from the creation of an object which is then
used in module_1.
What is the best way to make that object visible in the module_1
namespace ?
I guess that if I do an ' import module_1 ', I can make the object
visible with ' module_1.myObject = myObject ', but that won't work with
the from ... import * statement.

Thanks in advance for your help.

 

[Marc 'BlackJack' Rintsch]

I have an application started by a main.py file, which does a ' from
module_1 import * '.
main.py is responsible from the creation of an object which is then
used in module_1.
What is the best way to make that object visible in the module_1
namespace ?
I guess that if I do an ' import module_1 ', I can make the object
visible with ' module_1.myObject = myObject ', but that won't work with
the from ... import * statement.

Give the object as argument to functions in `module_1` is a clean solution.

Ciao,
Marc 'BlackJack' Rintsch

 

[Peter Otten]

I'm new to Python and have the following problem :
I have an application started by a main.py file, which does a ' from
module_1 import * '.
main.py is responsible from the creation of an object which is then
used in module_1.
What is the best way to make that object visible in the module_1
namespace ?
I guess that if I do an ' import module_1 ', I can make the object
visible with ' module_1.myObject = myObject ', but that won't work with
the from ... import * statement.

You can do both

from module import *
import module

as these kinds of import are not mutually exclusive.
But I recommend that you restructure your modules to avoid cyclic
dependencies.

Peter

 

[jdemoor]

Thanks for the replies.

You can do both

from module import *
import module

as these kinds of import are not mutually exclusive.

Would this run the code in 'module' twice, or just make the objects in
it accessible by several names ?

 

[Peter Otten]

Thanks for the replies.


Would this run the code in 'module' twice, or just make the objects in
it accessible by several names ?

The latter. But why don't you try it yourself by putting a

print "importing module" # you will see that once

statement in the module?

There is one notable exception, the application's main module:

$ cat main.py
import main
print "importing main as", __name__
$ python main.py
importing main as main
importing main as __main__

Peter

 

[Marc 'BlackJack' Rintsch]

Would this run the code in 'module' twice, or just make the objects in
it accessible by several names ?

The code at module level is only executed at first import.

Ciao,
Marc 'BlackJack' Rintsch

 

[jdemoor]

Ok, thanks again. That was helpful.