🐍 How to Learn Python from Scratch – Part 2: From Beginner to Mid-Level

👋 Hey there!

If you're here, that means you've already started your Python journey. Maybe you've printed "Hello, World!" or built a simple calculator. That’s awesome!

Now it's time to level up. In this part, you’ll learn the skills you need to move from beginner to mid-level Python developer — the kind of skills that help you build real projects, crack job interviews, and feel confident with code.

Let’s go! 🚀

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📌 Before You Begin

If you haven’t checked out Part 1 of this guide, go read that first — it shows you how to install Python, learn the basics, and start your journey:
👉 How to Learn Python from Scratch – Part 1

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🧭 Learning Roadmap – From Basics to Mid-Level

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1. 🔧 Object-Oriented Programming (OOP)

Why it’s important:
It helps you organize your code better and is used in most real-world apps and interviews.

• Class = A blueprint
• Object = A thing made from that blueprint
• __init__() = Special function that runs when the object is created
• Inheritance = One class can "copy" another
• Encapsulation = Hide details inside a class
• Polymorphism = Same function works differently depending on the object

class Dog:
    def __init__(self, name):
        self.name = name

    def speak(self):
        return f"{self.name} says Woof!"

class GuideDog(Dog):
    def speak(self):
        return f"{self.name} gives a soft bark."

dog1 = Dog("Bruno")
dog2 = GuideDog("Rex")

print(dog1.speak())  # Bruno says Woof!
print(dog2.speak())  # Rex gives a soft bark.

🛠 Mini Project: Bank Account system with deposit, withdraw, and balance features.

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2. 🚨 Error Handling

Why it’s important:
It helps your program not crash when something goes wrong.

• try / except
• else / finally
• Custom error messages

def divide(x, y):
    try:
        return x / y
    except ZeroDivisionError:
        print("Oops! Can't divide by zero.")
    finally:
        print("Function completed.")

print(divide(10, 2))
print(divide(10, 0))

🛠 Mini Project: Login system with error messages.

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3. 📂 File Handling

Why it’s important:
You can read/write files — great for notes, logs, etc.

• Open, write, and read files
• Use the csv module

# Write
with open("note.txt", "w") as f:
    f.write("Learning Python is fun!")

# Read
with open("note.txt", "r") as f:
    print(f.read())

🛠 Mini Project: Build a note-taking app.

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4. 📦 Modules and Packages

Why it’s important:
Keeps your code organized and reusable.

• Use built-in modules
• Create your own .py file
• Use if __name__ == "__main__"

# utils.py
def greet(name):
    return f"Hello, {name}!"

# main.py
import utils
print(utils.greet("Alex"))

🛠 Mini Project: Tools module (calculator, converters, etc.)

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5. 🔐 Virtual Environment & pip

Why it’s important:
Manages project dependencies safely.

python -m venv myenv
source myenv/bin/activate  # Mac/Linux
myenv\Scripts\activate     # Windows
pip install flask

🛠 Mini Project: Build a Flask "Hello World" app.

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6. 🌐 Working with APIs

Why it’s important:
Fetch live data like weather or users.

• Use requests
• Work with JSON

import requests

res = requests.get("https://randomuser.me/api/")
if res.status_code == 200:
    data = res.json()
    print("Random user:", data["results"][0]["name"]["first"])

🛠 Mini Project: Create a weather app using OpenWeatherMap API.

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7. 🧠 Data Structures & Algorithms

Why it’s important:
Essential for coding interviews and speed.

name = "Python"
age = 25
pi = 3.14
is_active = True
fruits = ["apple"]
dimensions = (1920, 1080)
unique = {1, 2, 3}
student = {"name": "Ali", "age": 20}

• Sorting: Bubble, Merge sort
• Searching: Linear, Binary
• Big O Notation

🛠 Practice: LeetCode, HackerRank, Exercism

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💡 What You Can Build After This

• Weather app with API
• Flask blog
• CLI note manager
• Auto-renaming tool
• Portfolio projects

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🛠 Tools You Should Learn

• Git & GitHub
• VS Code
• Jupyter Notebook
• Python Tutor

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🎯 Bonus: 100 Days of Code

• Code 30 min daily
• Post progress online
• Build projects

Plan:

• Days 1–10: Basics
• Days 11–30: OOP & Errors
• Days 31–60: Files & APIs
• Days 61–80: Modules & Flask
• Days 81–100: Projects

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✨ Final Words

Moving from beginner to mid-level is all about practice, patience, and projects. Don’t worry about mistakes — that’s how real learning happens.

Stay curious, build often, and get ready for Part 3 — covering web development, data science, and automation.

Till then, happy coding! 🐍💻

If anyone is interested in a project or anything, feel free to comment. I'd be happy to assist and collaborate with you!