why definition of function does locate before calling it in python code

 In Python, you must define a function before you can call it. This is because Python executes code line by line, and it needs to know what the function does before it can be used.

Here's why:

• Execution Order: Python reads and executes code line by line. If you try to call a function that hasn't been defined yet, Python won't recognize it and will raise a NameError.
• Readability and Maintainability: Defining functions before they are used generally improves code readability and maintainability. It allows you to organize your code into logical blocks and makes it easier to understand the flow of your program.

Example:

Python

# Function definition
def greet(name):
    print("Hello,", name + "!")

# Function call
greet("World")  

In this example, the greet function is defined first. Then, it is called with the argument "World". If you tried to call greet before it was defined, you would get a NameError.

Key Points:

• Function definitions are like blueprints for how a piece of code should work.
• Python needs to understand the blueprint before it can use it.
• Defining functions before they are used is generally considered good practice for code organization and readability.

I hope this explanation is helpful!