Modules
What is a Module
A module is a file containing a set of codes or a set of functions which can be included to an application. A module could be a file containing a single variable, a function or a big code base.
Creating a Module
To create a module we write our codes in a python script and we save it as a .py file. Create a file named mymodule.py inside your project folder. Let us write some code in this file.
Create main.py file in your project directory and import the mymodule.py file.
Importing a Module
To import the file we use the import keyword and the name of the file only.
Import Functions from a Module
We can have many functions in a file and we can import all the functions differently.
Import Functions from a Module and Renaming
During importing we can rename the name of the module.
Import Built-in Modules
Like other programming languages we can also import modules by importing the file/function using the key word import. Let's import the common module we will use most of the time. Some of the common built-in modules: math, datetime, os,sys, random, statistics, collections, json,re
Using python os module it is possible to automatically perform many operating system tasks. The OS module in Python provides functions for creating, changing current working directory, and removing a directory (folder), fetching its contents, changing and identifying the current directory.
The sys module provides functions and variables used to manipulate different parts of the Python runtime environment. Function sys.argv returns a list of command line arguments passed to a Python script. The item at index 0 in this list is always the name of the script, at index 1 is the argument passed from the command line.
Example of a script.py file:
Now to check how this script works I wrote in command line:
The result:
Some useful sys commands:
Statistics Module
The statistics module provides functions for mathematical statistics of numeric data. The popular statistical functions which are defined in this module: mean, median, mode, stdev etc.
Module containing many mathematical operations and constants.
Now, we have imported the math module which contains lots of function which can help us to perform mathematical calculations. To check what functions the module has got, we can use help(math), or dir(math). This will display the available functions in the module. If we want to import only a specific function from the module we import it as follows:
It is also possible to import multiple functions at once
But if we want to import all the function in math module we can use * .
When we import we can also rename the name of the function.
A string module is a useful module for many purposes. The example below shows some use of the string module.
By now you are familiar with importing modules. Let us do one more import to get very familiar with it. Let us import random module which gives us a random number between 0 and 0.9999.... The random module has lots of functions but in this section we will only use random and randint.
🌕 You are going far. Keep going! You have just completed day 12 challenges and you are 12 steps a head in to your way to greatness. Now do some exercises for your brain and muscles.
💻 Exercises: Day 12
Exercises: Level 1
Writ a function which generates a six digit/character random_user_id.
Modify the previous task. Declare a function named user_id_gen_by_user. It doesn’t take any parameters but it takes two inputs using input(). One of the inputs is the number of characters and the second input is the number of IDs which are supposed to be generated.
Write a function named rgb_color_gen. It will generate rgb colors (3 values ranging from 0 to 255 each).
Exercises: Level 2
Write a function list_of_hexa_colors which returns any number of hexadecimal colors in an array (six hexadecimal numbers written after #. Hexadecimal numeral system is made out of 16 symbols, 0-9 and first 6 letters of the alphabet, a-f. Check the task 6 for output examples).
Write a function list_of_rgb_colors which returns any number of RGB colors in an array.
Write a function generate_colors which can generate any number of hexa or rgb colors.