Python Crash Course for Beginners

Introduction

• Previous course used Eclipse IDE; now using VS Code.
• Lecture uses a Python sandbox from a Django course on Udemy.
• Sandbox contains starter files on strings, functions, classes, etc.

Setup

• Download Python 3 from the official site.
• Verify installation using python3 --version.
• Use VS Code’s integrated terminal for running Python scripts.

Variables and Data Types

• Variables are containers for values.
• No semicolons or var keyword needed in Python.
• Common data types: int, float, str, bool.
• Boolean values must capitalize True/False.
• Multiple assignment is possible in Python.
• Example: X, Y, name, is_cool = (1, 2.5, 'John', True).

Comments

• Single-line comment: # Comment
• Multi-line comment: ''' Comment ''' or """ Comment """

Strings

• Use single or double quotes.
• Concatenation with + operator.
• String formatting with f-strings and .format().

Lists

• Created using brackets [].
• Allows duplicate members and is ordered.
• Methods: append, remove, insert, pop, reverse, sort.
• Example: fruits = ['apple', 'orange']

Tuples

• Created using parentheses ().
• Ordered but unchangeable, duplicates allowed.
• Single value tuples need trailing comma.

Sets

• Created using braces {}.
• Unordered, unindexed, no duplicates allowed.
• Example methods: add, remove, clear.

Dictionaries

• Created using curly braces {} with key-value pairs.
• Changeable, unordered, indexed.
• Methods: keys, items, copy, clear.
• Access values using keys or .get() method.

Functions

• Defined with def keyword.
• Can have default parameters.
• Return values using return keyword.

Lambda Functions

• Anonymous functions using lambda keyword.
• Single-expression, returns value.

Conditionals

• Use if, elif, else without parentheses.
• Logical operators: and, or, not.
• Membership operators: in, not in.

Loops

• for loops iterate over sequences (lists, strings, etc.).
• while loops run while a condition is true.
• break to exit loop, continue to skip iteration.

Modules

• Import core modules or install external ones using pip.
• Example: import datetime, from datetime import date.
• Custom modules can be created and imported.

Classes

• Template for creating objects.
• Use class keyword.
• Constructors defined with __init__().
• Methods within class need self parameter.

Files

• Open, read, write, and delete files.
• Use open() with modes ('w', 'a', 'r+').
• Example: file = open('file.txt', 'w')

JSON

• Parse JSON to Python dictionary using json.loads().
• Convert dictionary to JSON using json.dumps().

Conclusion

• Basic concepts necessary for programming in Python.
• Recommended next steps: tutorials, books, or projects.
• Promo for a Django course associated with this lecture.