Python Programming Notes (Corrected & Improved)

1. What is Python Programming?

Python is a high-level, general-purpose programming language used for many types of software development such as web development, data science, automation, artificial intelligence, and scripting.

• It was created by Guido van Rossum.
• First released in 1991.
• Python is known for its simple and readable syntax, which makes it easy to learn.

✅ Added: Python supports multiple programming paradigms, including:

• Procedural programming
• Object-Oriented Programming (OOP)
• Functional programming

2. History of Python

There are not only two types of Python, but two major versions.

Python 2

• Released on October 16, 2000.
• Widely used for many years.
• The last version of Python 2 was Python 2.7, released in 2010.
• Official support ended on January 1, 2020.

Because of this, Python 2 is no longer recommended for new projects.

Python 3

• First released in 2008.
• It introduced major improvements and changes compared to Python 2.

Python 3 is not fully backward compatible with Python 2, meaning some Python 2 code will not work in Python 3 without modification.

✔ Python 3 is actively developed and updated, which is why it is the main version used today.

3. Difference Between Compiler and Interpreter

Interpreter

An interpreter translates and executes the code line by line.

Characteristics:

• Code is executed immediately.
• No separate machine-code file is created.
• If an error occurs, the program stops at that line.

Examples of interpreted languages:

• Python
• JavaScript
• Ruby

⚠️ Improvement:

Python actually compiles code to bytecode internally, then executes it using an interpreter.

Compiler

A compiler translates the entire program at once into machine code before execution.

Characteristics:

• Translation happens once.
• The compiled program is saved as an executable file.
• Execution is usually faster because translation is already done.

Examples of compiled languages:

• C
• C++
• Go

4. Difference Between Static and Dynamic

⚠️ Clarification: These terms are commonly used when talking about typing in programming languages.

Static

In static typing, the data type of a variable must be declared before using it, and it usually cannot change later.

Example (C++):

intage =20;

Characteristics:

• Type is checked at compile time
• Fewer runtime errors
• Faster execution

Examples:

• C
• C++
• Java

Dynamic

In dynamic typing, the data type is determined automatically while the program runs.

Example (Python):

age=20
age="twenty"

Characteristics:

• Type is determined at runtime
• Easier and faster to write code
• More flexible but may cause runtime errors

Examples:

• Python
• JavaScript
• Ruby

Quick Summary