Namespace

It is important to understand how varaible names are located when a program is executed. Python will search the local space that the program is running for the varaibel being utilised.If it cannot find the varailbe it will then search down the layers of classes and fucntions to find the value that is required.

Example 1 

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def function1(x):
    x = 4
    print (x)
    return x

def function2(x):
    x = 3
    function1(x)
    print (x)
    return x

def function3(x):
    x = 2
    function2(x)
    print (x)
    return x

x = 1

function3(x)
Returns:
1
2
3
4
3
2

Example 2

If we update the program above but we request a varaible in function 1 that is in the global namespace.
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def function1(x):
    x = 4
    print (x)
    print (y)
    return x

def function2(x):
    x = 3
    function1(x)
    print (x)
    return x

def function3(x):
    x = 2
    
    function2(x)
    print (x)
    return x

x = 1
y = 6
function3(x)
Returns:
1
2
3
4
4
6
3
2


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