What are python modules?

A Python module is a .py file containing executable code or a set of functions you want to include in your application. In short words It is a Python file containing Python statements and definitions.

Some of the commonly used modules are:

• os
• sys
• math
• random
• data time
• JSON

Additional information

Create a Module

To create a module just save the code you want in a file with the file extension .py:

def greeting(name):
  print("Hello, " + name) 

Use a Module

we can use the module we already created, by using the import statement:

import my_module

my_module.greeting("Ellie")

Note: When you are using a function from a module, use the syntax: module_name.function_name.

Some modules

• os: It provides functions for interacting with the operating system.

import os
cwd= os.getcwd()
print("Current working directory:", cwd)

Output:
Current working directory: /media/eli/Data/workplace/Git/Git/Top-100-Python-Interview

• sys: This module provides various functions and variables that are used to manipulate different parts of the Python runtime environment.

import sys
print(sys.version)

Output:
3.8.5 (default, May 27 2021, 13:30:53) 
[GCC 9.3.0]

• math: You can use this module for mathematical tasks. It have different methods.

math.pi provides a more precise value for the pi:

import math 
# Print the value of pi 
print (math.pi)

Output:
3.141592653589793

• random: With this module we can produce anything randomly. You can use this module in applications like tic-tac-toe, rock-paper-scissor, etc.

Here a example of a simple program to generate random integers from a range:

import random

# generating a random number from the range 1-100
print(random.randint(1, 100)) 

• data time: It is date and time object combinations.

import datetime

x = datetime.datetime.now()
print(x) 

• JSON: It can be used to work with JSON data.

import JSON

Runtime and compile runtime

• Compile-time: Is the moment where the code you entered is converted to executable.
• Run-time: Is the moment where the executable code is running.

References:

Python modules Sys module Data time module JSON module Os module Math module Random module