modules.md

Modules

Python modules allows us to reuse our own code or sometimes use somebody else's code. We can write our own modules or we can use modules written by someone else like requests,datetime and etc.

Note: It's just a python file.

Built-in Modules

There built-in python modules that come by default. List can be found here LIST OF MODULES

• We can import modules by using import keyword
• We can also give modules an alias when we have long module names like import random as r.
• We can also import few functions from the modules from random import randint.
• If you want to import everything from random we do something like this from random import *

Custom Modules

Custom module is just file with python code.

For Example

# file1.py
def hello():
    return "Hello"
def hey(name):
    return f'Hey {name}'

# Importing a custom module
import file1 as fn
fn.hello()
fn.hey('Jake')

External Modules

External modules can be found here PyPi

• We can install modules using pip, pip install <package-name>.
• Pip comes default in Python 3.4 we can run using python3 -m pip install <package-name>.
• print(dir(<package_name>)) This tells us about the attributes.
• print(help(package_name)) This tells us everything about the package

Using PEP8 to cleanup Code

• We can use autopep8 to fix whitespaces and ident our code
• We can use autopep8 --in-place <file_name>

The __name__ variable

• The __name__ variable usually refers to the file name if its the file then it will interpreted as __main__
• If it's a module then __name__ will be interpreted as the __file_name__.

Note : use if __name__ = '__main__'