Name of Module, Making our own modules in Python

Name of Module

Every module has a name. We can find the name of a module by using the __name__attribute of the module.

Actually, for every standalone program written by the user, the name of the module is _main_.

Example:

print("Hello")
print("Name of this module is:",__name__)

Output:

Hello

Name of this module is: __main__

Making our own modules

 We can easily create as many modules as we want.  Actually, every Python program is a module; that is, every file that we save as .py extension is a module.

Actually, Modules are placed in the same directory as that of the program in which it is imported. It can also be stored in one of the directories listed in the sys.path.

For example,

We are writing some codes in a file and save the file as john.py:

def display(): # function definition
    print("Welcome")
str="Welcome to the world of Python!!!" # variable definition

Now, we are opening another file (main.py) and write the lines of code given as follows:

import john
print("str=",john.str);
john.display()

After running the above code, we get the following output.

Output:

str= Welcome to the world of Python!!!

Welcome

Standard Library Modules

Python supports the following types of modules:

• Those written by the programmer.
• Those that are installed from external sources.
• Those that are pre-installed with Python.

Modules that are pre-installed in Python are together known as the standard library. Some useful modules in the standard library are string, re, datetime, math, random, os, multiprocessing, email, JSON, PDB, argparse, and sys.

We can use these modules for performing tasks like string parsing, data serialization, testing, debugging and manipulating dates, emails, command-line arguments, etc.

Example A:

import math
a=4
b=3
c=math.pow(a,b)
print("C=",c)

Output:

C= 64.0

Example  B:

import string
# string module constants
print(string.ascii_letters)
print(string.ascii_lowercase)
print(string.ascii_uppercase)
print(string.hexdigits)

Output:

abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ

abcdefghijklmnopqrstuvwxyz

ABCDEFGHIJKLMNOPQRSTUVWXYZ

0123456789abcdefABCDEF

Example  C:

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

Output:

2020-12-31 00:56:43.395602