As mentioned earlier, the **global scope** is your code's main scope (environment). Every script (`.py` file) has its global scope.

first = "This"
second = "is"
third = "the"
fourth = "main"
fifth = "scope"

print(first, second, third, fourth, fifth)

> Note
>
> There is only the **built-in** scope out of the global scope. 

We can use functionality from outer scopes in inner scopes. This means that we can use built-in functionality in the global scope as well as in local scopes, which are nested within the global scope.

Look at the example:

print(len("some string"))  # built-in objects usage

number = 15  # global scope

def print_number():
    print(number)  # global object usage

print_number()

In the example above, the global variable `number` is used inside the `print_number()` function local scope.

You can access variables and functions from outer scopes but cannot change them:

number = 221

def modify_global():
    number += 5

modify_global()
print(number)

You can access the change of a global variable/function using the `global` keyword:

number = 20
print(number)

def modify_global():
    global number
    number += 10

modify_global()
print(number)

modify_global()
print(number)

<details>
  <summary class='CodeD'>Code Description</summary>
  <div class="CodeD-text">
Explanation:<br>
<br>
<ol>
<li>The initial value of <code>number</code> is <code>20</code>. The first <code>print(number)</code> statement outputs <code>20</code>.</li>
<li>The <code>modify_global()</code> function is called, which uses the <code>global</code> keyword to access and modify the global variable <code>number</code>. It increments the value of <code>number</code> by <code>10</code>, resulting in <code>number</code> being <code>30</code>.</li>
<li>The second <code>print(number)</code> statement outputs <code>30</code>.</li>
<li>The <code>modify_global()</code> function is called again. This time, it increments the value of <code>number</code> (which is now <code>30</code>) by <code>10</code> again, resulting in <code>number</code> being <code>40</code>.</li>
<li>The third <code>print(number)</code> statement outputs <code>40</code>.</li>
</ol>
<br>
Since the <code>global</code> keyword allows you to modify the global variable <code>number</code> within the function's local scope, the value of <code>number</code> is changed and reflected in subsequent function calls. Without the <code>global</code> keyword, the function would treat <code>number</code> as a local variable and raise an <code>UnboundLocalError</code>, as seen in the previous example.
  </div> 
</details>

What scope is the main scope of your code?

Discover the secrets of Python's Scopes, Closure, and Decorators in this immersive course. Gain mastery over variable visibility, unlock the power of closures for flexible function creation, and learn how decorators can enhance and modify your code dynamically. Elevate your Python skills and unleash the full potential of your programming abilities.

Python code distributes variables and objects across different environments isolated from each other. They are called scops. Let's study them, shall we?

To learn closure, you must complete the previous section, "Scopes".  The closure is used for decorators, caching, and other programming tools.

Decorators are widely used in real development. They open up many possibilities for us, and it is worth knowing how they work. To understand decorators, you need to know scopes and closures.

Mastering Python: Closures and Decorators

Built-In and Global Scopes