Majid Baseer Not quite clear what you mean by 'built' functions. Assuming you mean precompiled functions with a C/C++ backend, called from Python, look at https://docs.python.org/3/extending/building.html and Numba https://numba.pydata.org/ for the JIT equivalent.

If your question is how to define/write your own functions, I suggest an introductory course in Python https://ocw.mit.edu/courses/6-0001-introduction-to-computer-science-and-programming-in-python-fall-2016/

Your university and/or the research computing arm of your university should have similar courses/workshops.

Dear Majid Baseer

Certainly! Here are some general tips for building functions in Python:

here's an example of a Python function that takes two numbers as inputs and returns their sum:

def add_numbers(num1, num2): """ This function takes two numbers as input and returns their sum. """ return num1 + num2

Let's break down this example:

• def is the keyword used to define a new function.
• add_numbers is the name of the function, which we chose to clearly convey its purpose.
• (num1, num2) are the function's inputs, separated by commas and enclosed in parentheses.
• The docstring enclosed in triple quotes explains what the function does and what inputs and outputs it requires.
• return num1 + num2 is the function's code. It adds num1 and num2 together and returns the result.

To call this function and use it in your program, you can simply pass in two numbers as arguments like this:

result = add_numbers(2, 3)

print(result) # Output: 5

In this example, we pass in the numbers 2 and 3 as arguments to add_numbers(), which returns their sum of 5. The value of result is then printed to the console.

In Python, you can define a function using the def keyword followed by the function name and the function parameters inside parentheses. The function block is then indented.

Here is an example of a simple function that takes two arguments and returns their sum:

def add_numbers(x, y): return x + y

In this example, add_numbers is the name of the function, and x and y are the parameters. The return statement specifies the value that the function will return when called.

Once you have defined a function, you can call it by its name and pass in arguments. Here is an example of how to call the add_numbers function:

result = add_numbers(2, 3) print(result)

This will output 5, which is the sum of 2 and 3.

You can also define functions that don't return any value by omitting the return statement or by using the return statement without any value. Here is an example:

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

In this example, the greet function takes a name parameter and prints a greeting message to the console. To call this function, you can do the following:

greet("John")

This will output Hello, John! to the console.