Python Start Learning

 Pareto Principle or the 80/20 Rule — the idea that roughly 20% of input (knowledge or effort) leads to 80% of output (results). When applied to Python, this means you only need to learn a core set of essential concepts to solve most real-world problems.

Here’s the 20% of Python that gives you 80% of the power:

---

🧠 1. Python Basics

• Variables and data types (int, float, str, bool)

• Input/output (input(), print())

• Comments (# for single-line, ''' ''' for multi-line)

---

🔁 2. Control Flow

• Conditional statements: if, elif, else

• Loops: for, while

• Loop control: break, continue, pass

---

📦 3. Data Structures

• Lists ([]) → Most used!

• Tuples (())

• Dictionaries ({} with key-value pairs)

• Sets (set())

Important operations:

• Slicing, indexing, appending, removing

• Iterating through collections

---

🧩 4. Functions

• Define with def

• Return values with return

• Parameters vs arguments

• Default arguments

• *args, **kwargs (optional but powerful)

---

🗂️ 5. Modules and Packages

• Importing: import math, from random import choice

• Using standard libraries (math, random, datetime, os)

---

🧰 6. Basic File Handling

• Opening files: open()

• Reading/writing text files

• with statement (context manager)

---

🐞 7. Error Handling

• Try-except blocks

• try, except, finally, raise

---

🧱 8. Object-Oriented Programming (Basics Only)

• Classes and Objects

• __init__ constructor

• Methods

• self keyword

---

🧹 9. List Comprehensions

• Shortcuts for creating lists:

  python
  squares = [x**2 for x in range(10)]
  

---

🔗 10. Useful Built-in Functions

• len(), range(), type(), str(), int(), sum(), sorted(), zip(), enumerate()

---

BONUS: Learn These Once You’re Comfortable

• Virtual environments (venv)

• pip for installing packages

• Writing and running .py files

• Working with libraries like pandas, matplotlib, requests, etc.

---

✅ How to Practice Efficiently:

1. Do small projects (calculator, to-do app, quiz game)

2. Practice on platforms like HackerRank, LeetCode, or Replit

3. Build 5–10 mini apps using only this core 20%