How do i use variable scope in python?



  • Variable scope is the scope of the variable and whether it is available outside of a method or inside of a method.

    Define a variable outside the method, and define one inside the method, then print the variable.

    >>> myvar = "carrot"
    >>> def best_cake(myvar):
                 print("We like " + myvar + " cake, I run before method is ran")
                 myvar = "fruit"
                 print("We like " + myvar + " cake, I run after method is ran")
        
    >>> print("I'm a global cake: " + str(myvar)) 
    

    I'm a global cake: carrot

    Run the method.

    >>> best_cake(myvar)
    

    We like carrot cake, I run before the method is run
    We like fruit cake, I run after the method is ran

    Conclusion: The global variable used until the method is run

    You can change the global variable by using the global statement.

    Add the statement "global myvar" to the code.

    >>> def best_cake():
               global myvar
               print("We like " + myvar + " cake, I run before the method is ran")
               myvar = "fruit"
              print("We like " + myvar + " cake, I run after the method is ran")
        
    >>> print("I'm a global cake: " + str(myvar)) 
    

    I'm a global cake: carrot

    Run the method.

    >>> best_cake()
    

    We like carrot cake, I run before the method is ran
    We like fruit cake, I run after the method is ran

    Print the global variable again. Notice, it change the variable from carrot to fruit.

    >>> print("We like " + myvar + " cake")
    

    We like fruit cake

    Conclusion: Using the global statement inside the method change the value of the variable outside of the method.


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