Receiving the instance of a already called module in another file without calling it again

Question

I have a question concerning variables and passing them to class methods. I have a script OM with the class OM in it.

class OM:
    def __init__( Self , Debug_Mode = False ):   
        print( "Initialized" )
        Self.Debug_Mode = Debug_Mode
        Self.Registered_Modules = { }

I also have this config script :

class Config:
    def __init__( Self ) :
        OM = __import__( 'OM' )
        Self.OM = OM.OM.Load_Module( )
        print( Self.OM )
        Self.Config_Entries = { }

As the script OM has been already called, I want to hand over the instance object WITHOUT calling it. For this reason, I printed 'Initialized' in my __init__ function.

When I execute my file, the "Initialized' string will be printed 2 times because it has been initialized before by my start script :

class VTE:
    def __init__( Self ) :  
        Self.OM = OM( Debug_Mode = False )
            
        CFG = Self.OM.Load_Module( 'Config' )               
        CFG.Config_Loader( ) 

What do I have to change here for importing the instance ( like <OM.OM object at x000002047D4ACC10> ) without calling it again :

OM = __import__( 'OM' )
Self.OM = OM.OM( )
print( Self.OM )
Self.Config_Entries = { }

Thanks a lot and best regards.

---

EDIT :

I now figured out how to do it. The instance of the module OM is in Self, so i defined a variable OM_Handler outside of __init__( ). Inside Of __init__, i assigned Self to OM_Handler :

class OM :
    
    OM_Handler = "None"
    
    def __init__( Self , Debug_Mode = False ) :
       
        OM.OM_Handler = Self
        Self.Debug_Mode = Debug_Mode
        Self.Registered_Modules = { }

Afterwards, i'm able to call the instance object in my config file :

class Config( ) :
    
    def __init__( Self ) :
        
        Self.Config_Entries = { }
               
        OM = __import__( 'OM' )
        OM_Handler = OM.OM.OM_Handler
        Self.OM = OM_Handler
        print( Self.OM )

Prints <OM.OM object at 0x0000026F5812DFA0>

But i'm not quite sure, if this is the best solution. I have been told, that global variables are strictly forbidden or rather have a bad repute.I hope, you will give me some advices.

Best regards NumeroUnoDE

Answer 1

You are confusing the concepts of "module" and "class" here. That distinction is especially important when you have a module and a class with the same name. If your INTENTION is to have a singleton OM object (one global for the whole app), you can do that by having OM.py look like this.

class OM:
    def __init__( self , Debug_Mode = False ):
        print( "Initialized" )
        self.Debug_Mode = Debug_Mode
        self.Registered_Modules = { }

OM = OM()

Now, in your main code, or in any module where you need it, you can write:

...
import OM

class Config():
    def __init__( self ):
        self.OM = OM.OM

Or, even simpler:

from OM import OM

class Config():
    def __init__( self ):
        self.OM = OM

It's not good practice to capitalize variable names, and it is ESPECIALLY bad to capitalize the name self. That spelling is an international standard in Python. It's not technically a reserved word, but it might as well be.