How to use threading module in Python?

Threading in Python is a way to run multiple threads (tasks, function calls) simultaneously.

Here is a simple example of how to use the threading module in Python.

```
import threading

This is the function that each thread will execute
def print_numbers(): for i in range(10): print(i)

This is another function that each thread will execute
def print_letters(): for letter in ‘abcdefghij’: print(letter)

Create threads
thread1 = threading.Thread(target=print_numbers)
thread2 = threading.Thread(target=print_letters)

Start the threads
thread1.start()
thread2.start()

Wait for both threads to complete
thread1.join()
thread2.join()
```

In this example, `print_numbers` and `print_letters` are executed simultaneously. The `Thread` object takes a function (and its arguments if any) as a target to be executed in a separate thread. The `start` method begins the execution of the threads, and the `join` method tells the program to wait for the threads to complete before moving on.

Note: In Python, because of the Global Interpreter Lock (GIL), even though the threading module is a way to achieve multitasking, it’s not actually taking advantage of multiple CPUs/cores as real parallel execution. If you’re looking for real parallel executing, you may want to look into using the multiprocessing module instead.