Theory & Concepts
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Python Core Concepts
Python
Summary
An overview of the core theoretical concepts for Python, covering fundamental principles and key ideas.
Detailed Notes
Python Core Concepts Python is a versatile, high-level programming language known for its readability and simplicity. These notes cover the foundational concepts that are essential for any Python programmer. 1. Data Types and Variables Python is dynamically typed, which means you don't need to declare a variable's type. The interpreter infers it at runtime. Strings (str): Textual data, enclosed in single or double quotes. Example: 'hello', "world". Numbers: Integers (int): Whole numbers, like 10 or -5. Floats (float): Numbers with a decimal point, like 3.14 or -0.01. Booleans (bool): Represent truth values, either True or False. Good Practice: Use descriptive variable names (e.g., user_name instead of un) to make your code more understandable. 2. Control Flow Control flow directs the order in which your code is executed. if-elif-else: Used for conditional logic. The code block under the first true condition is executed. for loops: Iterate over a sequence (like a list, tuple, or string). Example: for item in my_list:. while loops: Repeat a block of code as long as a condition remains true. Be careful to avoid infinite loops! 3. Data Structures Python offers several built-in data structures to store collections of data. Lists: Ordered and mutable (changeable). Defined with square brackets []. Great for sequences of items that may need to be modified. Tuples: Ordered and immutable (unchangeable). Defined with parentheses (). Used for data that should not change, like coordinates. Dictionaries: Unordered collections of key-value pairs. Defined with curly braces {}. Extremely efficient for looking up values by a key. Sets: Unordered collections of unique items. Useful for membership testing and eliminating duplicate entries. 4. Object-Oriented Programming (OOP) Python is a fully object-oriented language. OOP helps in structuring code into reusable blueprints called classes. A class is the blueprint for creating objects. The __init__() method is the constructor, which is called when a new object (instance) is created. Inheritance allows a new class (child) to inherit attributes and methods from an existing class (parent), promoting code reuse.