Python Programming Course Notes

Jul 30, 2024

Notes on Python Programming Course

Introduction to Python

  • Python popularity: Powerful, easy to learn, highly sought after for jobs.
  • Use cases: Automating tasks, writing scripts, general programming.
  • Beginner-friendly: Simple syntax, no steep learning curve.

Installing Python and Setting Environment

Steps to Install Python:

  1. Go to python.org/downloads
  2. Choose between Python 2 or Python 3:
    • Python 2 is legacy, not actively maintained.
    • Python 3 is the current version and recommended for beginners.
  3. Click “Download Python 3.x.x” (latest version).
  4. Follow installer instructions.

Setting Up a Text Editor (IDE):

Writing Your First Python Program

Hello World Example:

print("hello world")

Structure of Python Programs:

  • Indentation is crucial. Indicating blocks of code.

Variables in Python

  • Definition: Containers for storing data.
  • Example:
character_name = "George"  
character_age = 70
  • Syntax types: Usually use underscores for readability.

Basic Python Operations

Print Statement:

  • Shows output on the console.

Working with Strings

String Operations:

  • Concatenation (+)
  • String functions:
    • .lower(), .upper(), .isupper(), .len()

Example:

phrase = 'Draft Academy'
print(phrase.upper())

Working with Numbers

  • Arithmetic operations: +, -, *, /
  • Modulus operator %: gives remainder of division.
  • Functions for math operations: abs(), pow(), max(), etc.

Input from Users

  • Getting input:
name = input("Enter your name: ")

Control Structures

If Statements:

  • Basic Syntax:
if condition:
     # do something  
elif other_condition:
     # do another thing  
else:
     # do a fallback action

For Loops:

  • Iterates over items in a collection.
for item in collection:
    # do something

While Loops:

  • Continues executing while a condition is true.
while condition:
    # do something

Collections in Python

Lists:

  • Definition: Store multiple items.
  • Accessing items: Use index.

Dictionaries:

  • Store key-value pairs.
  • Example:
days = {'mon': 'Monday', 'tue': 'Tuesday'}

Classes and Objects:

  • Class: Blueprint for creating objects.
  • Object: Instance of class.
  • Example: A student class with attributes for name, major, GPA.

Inheritance:

  • Allows class to inherit attributes and methods from another class.

Error Handling

  • Use try...except blocks to catch and handle errors without stopping program execution.
  • Follow best practices by catching specific exceptions.

Working with Files

Opening Files:

  • Open a file with open('filename', 'r')

Reading Files:

  • Use read(), readline(), or readlines() for file operations.

Using Modules

  • Import custom and external modules with import statement.
  • Example of third-party libraries: NumPy, pandas.

Summary

  • Comments in Python: Use # for single-line comments and ''' for multi-line.
  • Importance of code organization with functions, loops, and classes.