day-09

Modules and Packages

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Code organization is crucial for maintaining and reusing code efficiently. We'll explore how Python's modules and packages help us achieve this.

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Module Definition and Creation

A module is a self-contained Python file that holds code elements like variables, functions, and classes. Modules keep code organized and maintainable.

• Creating Modules

  • We'll create a module (e.g., math_operations.py) with functions (e.g., add and subtract) and demonstrate how to use it in another Python script.

  Example Code:

  # name of file: math_operations.py
  def add(a, b):
      return a + b
  
  def subtract(a, b):
      return a - b

  # name of file: main.py
  import math_operations
  
  result_add = math_operations.add(5, 3)
  result_subtract = math_operations.subtract(10, 4)

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Built-in Modules

Python offers built-in modules for various tasks. These modules provide specialized functions for common operations.

• Using the math Module

  • We'll use the math module to calculate the square root of a number, showcasing how built-in modules save coding time.

  Example Code:

  import math
  
  result_sqrt = math.sqrt(16)

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Organizing Code with Packages

• What are Packages?

  • Packages are directories that group related modules together, making it easier to manage larger projects.

• Creating and Using Packages

  • We'll create a package (e.g., mypackage) with multiple modules and illustrate how to use the modules within the package.

  Example Code:

  mypackage/  # folder name
  ├── __init__.py  # file 
  ├── module1.py   # file 
  ├── module2.py   # file 

  # name of file: main.py
  from mypackage import module1, module2
  
  result1 = module1.some_function()
  result2 = module2.another_function()

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Selective Imports

Python allows us to import only the specific functions or variables we need from a module. This reduces memory usage and enhances code clarity.

Example Code:

from math_operations import add

result_add = add(8, 2)

from math_operations import subtract

result_subtract = subtract(15, 5)

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Additional Resource:

• Python Modules and Packages

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CHALLENGE TIME!!!

You are tasked with creating a module that calculates the area of a circle based on its radius. You should import this module and use it to find the area of a circle with a radius of 5.

Example Code:

# name of file: square_area.py

def calculate_area(side):
    return side * side

# name of file: main.py
from square_area import calculate_area

side = 5
area = calculate_area(side)