0 Basic python-16.5 The modification of global variables between modules and other methods of accessing global variables

In this chapter, we will discuss the changes of global variables between modules in Python and other methods for accessing global variables.

1. Modification of global variables between modules

x=1# global variables, is actually the module inside all functions can use Def test ():    print (x) if __name__== ' __main__ ':                     Test ()

The above code is saved as test.py

Import testif __name__== ' __main__ ':        test.x=2        test.test ()        print (test.x)

The above code is saved as test2.py

We run test2.py

Output:

Although the above code implements the modification of global variables between modules, we do not recommend this approach because there are a lot of changes in large applications, and if this cross-module modification is cumbersome for future maintenance

2. Other ways to access global variables

x=1# global variables, in fact, all the functions inside the module can use Def test1 ():    x=6    print (' test1: ' +str (x)) def test2 ():    Global x    x+=1    Print (' Test2: ' +str (x)) def test3 ():    import test    test.x+=1    print (' Test3: ' +str (test.x)) def test4 ():    Import sys    module=sys.modules [' Test ']    module.x+=1    print (' test4: ' +str (module.x)) if __name__== ' __ Main__ ':                     test1 ()        test2 ()        test3 ()        test4 ()        print (x)

The above code is saved as test.py

Run output:

From the above results can be seen, although the others have changed, but the final x is only because the use of the global that sentence to guess the change, the other to no change

Summary: This chapter briefly introduces the modification of global variables between modules and other methods for accessing global variables.

This chapter is here, thank you.

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0 Basic python-16.5 The modification of global variables between modules and other methods of accessing global variables