Google Gemma Free Model, Run AI Locally, Open Weights vs Open Source, Ollama Gemma Setup.

आजकल यूट्यूब और टेक जगत में Gemma को लेकर काफी चर्चा है। जहाँ Gemini एक क्लाउड-आधारित AI है, वहीं Gemma को खास तौर पर उन लोगों के लिए बनाया गया है जो अपने खुद के सिस्टम पर बिना इंटरनेट के AI चलाना चाहते हैं।

Gemma क्या है?

Gemma, Google द्वारा विकसित "Open Weight" मॉडल्स की एक श्रृंखला है। इसे उसी तकनीक पर बनाया गया है जिससे Gemini बना है, लेकिन यह पोर्टेबल है और इसे कोई भी डाउनलोड करके इस्तेमाल कर सकता है।

क्या यह सच में Free और Offline है?

जी हाँ, इसकी सबसे बड़ी खासियत यही है:

• स्थानीय उपयोग (Local Use): एक बार डाउनलोड होने के बाद इसे चलाने के लिए इंटरनेट की कोई ज़रूरत नहीं होती।
• अनलिमिटेड एक्सेस: आप इसे बिना किसी सब्सक्रिप्शन फीस के जितनी बार चाहें उतनी बार इस्तेमाल कर सकते हैं।
• डेटा प्राइवेसी: आपकी बातचीत आपके ही कंप्यूटर पर रहती है, कहीं बाहर नहीं जाती।

तकनीकी तुलना

फीचर	Gemini (Cloud)	Gemma (Open)
इंटरनेट	अनिवार्य	Offline संभव
लागत (Cost)	Subscription (Pro के लिए)	पूरी तरह Free
कस्टमाइज़ेशन	सीमित	Full (डेवलपर्स के लिए)

इसे कैसे चलाएं?

अगर आप इसे अपने कंप्यूटर पर टेस्ट करना चाहते हैं, तो Ollama या LM Studio जैसे टूल्स का उपयोग कर सकते हैं। ये टूल्स आपको कुछ ही मिनटों में मॉडल सेटअप करने की सुविधा देते हैं।

---

तकनीक और AI से जुड़ी ऐसी ही जानकारियों के लिए हमारे ब्लॉग से जुड़े रहें।

Blogging Guide: SEO

SEO के गुप्त राज"

How to increase blog traffic" और "Google Search Console errors fix

Artificial Intelligence AI Explained What is AI AI Technology Machine Learning basics Deep Learning guide AI future impact AI applications in real life Benefits of Artificial Intelligence AI risks and challenges What is artificial intelligence in simple words How AI works step by step Future of AI in 2030 AI vs human intelligence Beginner guide to artificial intelligence

Also Read: How Modern Technology is Changing the Future

Frequently Asked Questions (FAQ)

What is Artificial Intelligence?

AI is the ability of machines to think, learn, and make decisions like humans.

Is AI dangerous?

AI can be risky if not used properly, but it is highly beneficial when controlled responsibly.

Will AI replace jobs?

AI will change jobs, but also create new opportunities.

---

Lesson 20: Python File Handling and Advanced I/O | Coding Class Series

Introduction

Welcome to Lesson 20!
In this lesson, we will learn file handling in Python, including reading, writing, appending, and advanced I/O operations.
File handling is essential to store and retrieve data for programs.

---

1. Opening a File

Python uses the open() function to work with files.

Syntax:

file = open("filename.txt", "mode")

Modes:

• "r" – Read (default)
• "w" – Write (creates new file or overwrites)
• "a" – Append (adds content at the end)
• "r+" – Read and Write

Example:

file = open("sample.txt", "w")
file.write("Hello, World!")
file.close()

---

2. Reading from a File

file = open("sample.txt", "r")
content = file.read()
print(content)
file.close()

Other reading methods:

• readline() – reads one line at a time
• readlines() – reads all lines into a list

file = open("sample.txt", "r")
print(file.readline())
print(file.readlines())
file.close()

---

3. Writing and Appending

• Writing overwrites the file:

file = open("sample.txt", "w")
file.write("New content here.")
file.close()

• Appending adds data to the end:

file = open("sample.txt", "a")
file.write("\nThis line is appended.")
file.close()

---

4. Using with Statement

The with statement automatically closes the file:

with open("sample.txt", "r") as file:
    content = file.read()
    print(content)

with open("sample.txt", "a") as file:
    file.write("\nAdding new line safely.")

---

5. Advanced I/O

• Binary files – "rb" and "wb" modes for reading/writing binary files.
• File positioning – seek() and tell() methods.

with open("sample.txt", "r") as file:
    print(file.tell())  # Current position
    print(file.read(5)) # Read 5 characters
    file.seek(0)        # Move pointer to start

• Checking file existence using os module:

import os
if os.path.exists("sample.txt"):
    print("File exists")
else:
    print("File does not exist")

---

6. Practice Exercises

1. Create a text file and write 5 lines of your choice.
2. Read the file and print each line one by one.
3. Append 3 more lines to the same file.
4. Use seek() and tell() to read specific parts of the file.
5. Try opening a file in binary mode and read/write some data.

---

---

Lesson 19: Python Classes, Objects, and OOP | Coding Class Series

Introduction

Welcome to Lesson 19!
In this lesson, we will learn about Object-Oriented Programming (OOP) in Python, including classes, objects, attributes, and methods.
OOP helps in writing organized, reusable, and modular code.

---

1. What is a Class?

A class is a blueprint for creating objects.
It defines attributes (data) and methods (functions) that the objects will have.

Example:

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

    def bark(self):
        print(f"{self.name} says Woof!")

---

2. Creating Objects

my_dog = Dog("Buddy", "Golden Retriever")
print(my_dog.name)  # Output: Buddy
print(my_dog.breed) # Output: Golden Retriever
my_dog.bark()       # Output: Buddy says Woof!

---

3. Instance vs Class Attributes

• Instance attributes – unique for each object
• Class attributes – shared by all objects

Example:

class Dog:
    species = "Canis familiaris"  # class attribute

    def __init__(self, name, breed):
        self.name = name           # instance attribute
        self.breed = breed

dog1 = Dog("Buddy", "Golden Retriever")
dog2 = Dog("Max", "Beagle")

print(dog1.species)  # Canis familiaris
print(dog2.species)  # Canis familiaris

---

4. Methods

Methods are functions inside classes:

• Instance methods – operate on instance data
• Class methods – operate on class data
• Static methods – utility methods that don’t access class or instance data

Example:

class Circle:
    pi = 3.14159

    def __init__(self, radius):
        self.radius = radius

    def area(self):
        return Circle.pi * self.radius ** 2

c = Circle(5)
print(c.area())  # Output: 78.53975

---

5. Inheritance

Inheritance allows a class to use attributes and methods of another class.

Example:

class Animal:
    def eat(self):
        print("Eating")

class Dog(Animal):
    def bark(self):
        print("Woof!")

dog = Dog()
dog.eat()  # Eating
dog.bark() # Woof!

---

6. Practice Exercises

1. Create a class Car with attributes make, model, and year, and a method to display info.
2. Create two objects of Car and print their details.
3. Add a class method to count the number of cars created.
4. Implement inheritance with a Truck class derived from Car with an extra method load_cargo.

---

 

---

Lesson 18: Python Error Handling, Exceptions, and Debugging | Coding Class Series

Introduction

Welcome to Lesson 18!
In this lesson, we will learn about handling errors in Python, using exceptions, and debugging techniques.
Error handling ensures that your program does not crash unexpectedly and behaves predictably.

---

1. Common Errors in Python

• SyntaxError – Mistake in code structure
• NameError – Using a variable before defining it
• TypeError – Using incompatible data types
• ValueError – Wrong type of value for a function
• ZeroDivisionError – Dividing a number by zero

Example:

# SyntaxError example
# print("Hello World"

# NameError example
# print(x)

---

2. Handling Exceptions with try-except

try:
    num = int(input("Enter a number: "))
    result = 10 / num
    print("Result:", result)
except ZeroDivisionError:
    print("Error: Cannot divide by zero!")
except ValueError:
    print("Error: Invalid input! Enter a number.")

---

3. Using else and finally

try:
    num = int(input("Enter a number: "))
    result = 10 / num
except Exception as e:
    print("Error occurred:", e)
else:
    print("Division successful! Result is", result)
finally:
    print("This block always executes")

---

4. Raising Custom Exceptions

def check_age(age):
    if age < 18:
        raise ValueError("Age must be at least 18")
    else:
        print("Access granted")

try:
    check_age(15)
except ValueError as e:
    print("Error:", e)

---

5. Debugging Techniques

• Use print statements to check variable values
• Use Python debugger (pdb) for step-by-step execution:

import pdb

def add(a, b):
    pdb.set_trace()
    return a + b

result = add(5, "10")  # This will raise TypeError
print(result)

• Use IDE debugging tools (VS Code, PyCharm)

---

6. Practice Exercises

1. Write a program that divides two numbers and handles all possible exceptions.
2. Create a function to calculate square root, raise a custom exception if the number is negative.
3. Debug a program that adds a string to a number and fix it using try-except.
4. Use finally to close a file after reading its contents, even if an error occurs.

---

---

Lesson 17: Python File Handling and Working with CSV/JSON | Coding Class Series

Introduction

Welcome to Lesson 17!
In this lesson, we will learn how to read and write files in Python and work with CSV and JSON data formats.
File handling is essential to store, retrieve, and process data in Python programs.

---

1. Working with Text Files

Python provides the open() function to work with files.

Modes:

• 'r' – Read (default)
• 'w' – Write (creates or overwrites file)
• 'a' – Append (add to file)
• 'r+' – Read and Write

Example: Writing and reading a text file

# Write to a file
with open("example.txt", "w") as f:
    f.write("Hello, Python File Handling!\n")
    f.write("This is Lesson 17.\n")

# Read from the file
with open("example.txt", "r") as f:
    content = f.read()
    print(content)

---

2. Reading Files Line by Line

with open("example.txt", "r") as f:
    for line in f:
        print(line.strip())

---

3. Appending Data to a File

with open("example.txt", "a") as f:
    f.write("Appending a new line.\n")

---

4. Working with CSV Files

Python provides the csv module to work with CSV data.

Writing CSV:

import csv

data = [["Name", "Age", "City"],
        ["Alice", 25, "New York"],
        ["Bob", 30, "London"]]

with open("people.csv", "w", newline="") as file:
    writer = csv.writer(file)
    writer.writerows(data)

Reading CSV:

import csv

with open("people.csv", "r") as file:
    reader = csv.reader(file)
    for row in reader:
        print(row)

---

5. Working with JSON Files

Python provides the json module to work with JSON data.

Writing JSON:

import json

person = {
    "name": "Alice",
    "age": 25,
    "city": "New York"
}

with open("person.json", "w") as f:
    json.dump(person, f, indent=4)

Reading JSON:

import json

with open("person.json", "r") as f:
    data = json.load(f)
    print(data)

---

6. Practice Exercises

1. Create a text file notes.txt, write multiple lines, and read them line by line.
2. Create a CSV file for your favorite movies (Title, Director, Year) and read it back.
3. Create a JSON file containing 3 student records with name, age, and grade. Read and display them in Python.
4. Append new data to both CSV and JSON files.

---

---

Lesson 16: Python Modules, Packages, and Pip | Coding Class Series

Introduction

Welcome to Lesson 16!
In this lesson, we will learn about Python modules and packages, how to import them, and how to install external libraries using pip.
Modules and packages help you organize code and reuse functionality efficiently.

---

1. What is a Module?

A module is a file containing Python code (functions, classes, variables).
You can reuse modules in multiple programs.

Example: math module

import math

print(math.sqrt(16))  # Output: 4.0
print(math.pi)        # Output: 3.141592653589793

---

2. Importing Modules

You can import a module in different ways:

# Import the whole module
import math
print(math.factorial(5))  # Output: 120

# Import specific functions
from math import factorial, ceil
print(factorial(6))  # Output: 720
print(ceil(4.2))     # Output: 5

# Import with alias
import math as m
print(m.sqrt(25))    # Output: 5.0

---

3. Creating Your Own Module

You can create a module by saving functions in a .py file.

my_module.py

def greet(name):
    return f"Hello, {name}!"

def add(a, b):
    return a + b

main.py

import my_module

print(my_module.greet("Alice"))
print(my_module.add(10, 5))

---

4. What is a Package?

A package is a folder containing multiple modules and an __init__.py file.
It allows better organization of related modules.

Example structure:

my_package/
    __init__.py
    module1.py
    module2.py

Usage:

from my_package import module1
module1.function_name()

---

5. Installing External Libraries with pip

pip is the Python package manager. You can install external libraries easily.

# Install a library
pip install requests

# Check installed libraries
pip list

Example usage:

import requests

response = requests.get("https://api.github.com")
print(response.status_code)  # Output: 200

---

6. Upgrading and Uninstalling Packages

# Upgrade a package
pip install --upgrade requests

# Uninstall a package
pip uninstall requests

---

7. Practice Exercises

1. Create a module calculator.py with functions for addition, subtraction, multiplication, and division. Import it in another program.
2. Organize two modules (math_ops.py and string_ops.py) into a package my_utils. Import and use functions.
3. Install the numpy library using pip and create an array.
4. Upgrade numpy and then uninstall it using pip commands.

---

---

Lesson 15: Python Exception Handling and Debugging | Coding Class Series

Introduction

Welcome to Lesson 15!
In this lesson, we will learn how to handle errors in Python programs using exceptions and debug our code.
Exception handling is important to prevent program crashes and manage unexpected situations gracefully.

---

1. What is an Exception?

An exception is an error that occurs during the execution of a program.
Common examples:

• Division by zero
• File not found
• Index out of range

# Division by zero
a = 10
b = 0
print(a / b)  # Raises ZeroDivisionError

---

2. Try and Except

Use try and except to catch and handle exceptions.

try:
    a = 10
    b = 0
    print(a / b)
except ZeroDivisionError:
    print("Error: Cannot divide by zero!")

---

3. Handling Multiple Exceptions

You can handle different types of exceptions separately.

try:
    numbers = [1, 2, 3]
    print(numbers[5])
    a = 10 / 0
except IndexError:
    print("Index not found in the list!")
except ZeroDivisionError:
    print("Cannot divide by zero!")

---

4. Using else and finally

• else: runs if no exception occurs
• finally: always runs, even if an exception occurs

try:
    a = 10
    b = 2
    print(a / b)
except ZeroDivisionError:
    print("Error: Cannot divide by zero!")
else:
    print("Division successful!")
finally:
    print("This runs always!")

---

5. Raising Exceptions

You can manually raise exceptions using raise.

age = -5

if age < 0:
    raise ValueError("Age cannot be negative!")

---

6. Debugging Tips

• Print statements: Check the values of variables at different points.
• Python debugger (pdb): Step through code line by line.
• IDE debugging tools: PyCharm, VS Code allow breakpoints and watches.

import pdb

x = 5
y = 0

pdb.set_trace()  # Start debugging here
z = x / y
print(z)

---

7. Practice Exercises

1. Write a program that asks the user for two numbers and divides them. Handle division by zero errors.
2. Open a file that may not exist and handle FileNotFoundError.
3. Raise an exception if a user's input string length is less than 5.
4. Use pdb to debug a program that calculates the factorial of a number.

---

---

Lesson 14: Python File Handling and CSV/JSON | Coding Class Series

Introduction

Welcome to Lesson 14!
In this lesson, we will learn how to work with files in Python, including reading, writing, and updating text files, as well as working with CSV and JSON formats.
File handling is essential for storing data permanently and exchanging it between programs.

---

1. Opening and Closing Files

Use the open() function to open a file. Always close it after use.

# Open a file in write mode
file = open("example.txt", "w")
file.write("Hello, Python!")
file.close()

# Open the file in read mode
file = open("example.txt", "r")
print(file.read())  # Hello, Python!
file.close()

---

2. Using with Statement

with automatically closes the file after usage.

with open("example.txt", "w") as f:
    f.write("Using with statement!")

with open("example.txt", "r") as f:
    print(f.read())  # Using with statement!

---

3. Reading Files

• read(): reads the entire file
• readline(): reads one line at a time
• readlines(): reads all lines into a list

with open("example.txt", "r") as f:
    print(f.readline())
    print(f.readlines())

---

4. Writing and Appending Files

• "w" mode: write (overwrites existing content)
• "a" mode: append (adds new content)

with open("example.txt", "a") as f:
    f.write("\nAppending a new line!")

with open("example.txt", "r") as f:
    print(f.read())

---

5. Working with CSV Files

CSV (Comma Separated Values) files store tabular data.

import csv

# Writing to a CSV file
with open("students.csv", "w", newline="") as csvfile:
    writer = csv.writer(csvfile)
    writer.writerow(["Name", "Age", "Grade"])
    writer.writerow(["Alice", 14, "A"])
    writer.writerow(["Bob", 15, "B"])

# Reading from a CSV file
with open("students.csv", "r") as csvfile:
    reader = csv.reader(csvfile)
    for row in reader:
        print(row)

---

6. Working with JSON Files

JSON is widely used for data exchange between applications.

import json

# Writing JSON to a file
data = {
    "name": "Alice",
    "age": 14,
    "subjects": ["Math", "English", "Science"]
}

with open("data.json", "w") as jsonfile:
    json.dump(data, jsonfile)

# Reading JSON from a file
with open("data.json", "r") as jsonfile:
    loaded_data = json.load(jsonfile)
    print(loaded_data["name"])  # Alice

---

7. Practice Exercises

1. Create a text file notes.txt and write 5 of your favorite quotes.
2. Create a CSV file inventory.csv for a shop with columns: Item, Quantity, Price. Read it and calculate total value.
3. Create a JSON file with your friends' details (name, age, city) and load it back in Python.
4. Read a text file and count the number of words in it.

---

---

Lesson 13: Python Classes and Object-Oriented Programming (OOP) | Coding Class Series

Introduction

Welcome to Lesson 13!
In this lesson, we will learn about Object-Oriented Programming (OOP) in Python, including classes, objects, methods, and inheritance.
OOP helps you structure your code in a way that models real-world objects and makes programming more organized and reusable.

---

1. What is a Class?

A class is a blueprint for creating objects. It defines attributes (data) and methods (functions).

# Define a class
class Dog:
    def __init__(self, name, age):
        self.name = name
        self.age = age
    
    def bark(self):
        print(f"{self.name} says Woof!")

---

2. Creating Objects

An object is an instance of a class.

# Create objects
dog1 = Dog("Buddy", 3)
dog2 = Dog("Max", 5)

print(dog1.name)  # Buddy
dog2.bark()       # Max says Woof!

---

3. The __init__ Method

• __init__ is a constructor used to initialize objects.
• self refers to the instance of the class.

class Cat:
    def __init__(self, name, color):
        self.name = name
        self.color = color
    
    def meow(self):
        print(f"{self.name}, the {self.color} cat, says Meow!")

---

4. Methods

Methods are functions inside classes that operate on objects.

class Circle:
    def __init__(self, radius):
        self.radius = radius
    
    def area(self):
        return 3.1416 * self.radius ** 2
    
    def perimeter(self):
        return 2 * 3.1416 * self.radius

c = Circle(5)
print(c.area())       # 78.54
print(c.perimeter())  # 31.416

---

5. Inheritance

Inheritance allows a class to inherit attributes and methods from another class.

class Animal:
    def speak(self):
        print("Some sound")

class Dog(Animal):
    def speak(self):
        print("Woof Woof")

class Cat(Animal):
    def speak(self):
        print("Meow Meow")

d = Dog()
c = Cat()
d.speak()  # Woof Woof
c.speak()  # Meow Meow

---

6. Encapsulation

Encapsulation hides data inside a class using private attributes.

class BankAccount:
    def __init__(self, balance):
        self.__balance = balance  # private variable
    
    def deposit(self, amount):
        self.__balance += amount
    
    def get_balance(self):
        return self.__balance

account = BankAccount(1000)
account.deposit(500)
print(account.get_balance())  # 1500

---

7. Polymorphism

Polymorphism allows objects of different classes to be used interchangeably.

class Bird:
    def speak(self):
        print("Tweet")

class Dog:
    def speak(self):
        print("Woof")

def make_speak(animal):
    animal.speak()

b = Bird()
d = Dog()
make_speak(b)  # Tweet
make_speak(d)  # Woof

---

8. Practice Exercises

1. Create a class Student with attributes name, roll_no, marks. Write a method to calculate percentage.
2. Create a class Vehicle and inherit it with Car and Bike. Add different methods to each.
3. Implement encapsulation for a Library class where books is private.
4. Write a program demonstrating polymorphism with two different classes.

---

---

Lesson 12: Python Exception Handling and Debugging | Coding Class Series

Introduction

Welcome to Lesson 12!
In this lesson, we will learn how to handle errors in Python using exceptions and use debugging techniques to make our programs more robust and error-free. Exception handling ensures that your program does not crash unexpectedly.

---

1. What is an Exception?

An exception is an error that occurs during program execution.
Examples: ZeroDivisionError, FileNotFoundError, ValueError.

# Example: Division by zero
a = 10
b = 0
print(a / b)  # This will cause ZeroDivisionError

---

2. Using try and except

The try block contains code that might raise an exception.
The except block handles the exception gracefully.

try:
    a = 10
    b = 0
    result = a / b
except ZeroDivisionError:
    print("Error: Cannot divide by zero!")

---

3. Handling Multiple Exceptions

You can catch multiple types of exceptions:

try:
    num = int(input("Enter a number: "))
    result = 10 / num
except ZeroDivisionError:
    print("Error: Division by zero!")
except ValueError:
    print("Error: Invalid input, not a number!")

---

4. Using else and finally

• else → Executes if no exception occurs
• finally → Executes always, even if an exception occurs

try:
    file = open("example.txt", "r")
except FileNotFoundError:
    print("File not found!")
else:
    print(file.read())
finally:
    print("Execution finished.")

---

5. Raising Exceptions

You can raise your own exceptions using raise:

age = int(input("Enter your age: "))
if age < 18:
    raise ValueError("You must be 18 or older to proceed.")

---

6. Debugging Techniques

1. Print statements – Track variable values and flow.
2. Using IDE debugger – Step through code line by line.
3. Logging module – Log errors for later analysis.

import logging

logging.basicConfig(filename="app.log", level=logging.ERROR)

try:
    x = 10 / 0
except ZeroDivisionError as e:
    logging.error("An error occurred: %s", e)

---

7. Practice Exercises

1. Write a program that asks for two numbers and divides them. Handle ZeroDivisionError and ValueError.
2. Open a file safely using try-except-else-finally.
3. Raise a custom exception if a user enters a negative number.
4. Implement logging to record all exceptions in your program.

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Lesson 11: Python File Handling and I/O | Coding Class Series

Introduction

Welcome to Lesson 11!
In this lesson, we will learn how to work with files in Python, including reading, writing, and appending data. File handling is crucial for data storage, logs, and application input/output.

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1. Opening a File

Use the built-in open() function to open a file:

# Open a file in read mode
file = open("example.txt", "r")
print(file.read())
file.close()

Modes of File:

• "r" → Read (default)
• "w" → Write (creates or overwrites)
• "a" → Append (adds data at end)
• "rb" / "wb" → Read/Write in binary mode

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2. Reading Files

• Read all content at once:

with open("example.txt", "r") as file:
    content = file.read()
    print(content)

• Read line by line:

with open("example.txt", "r") as file:
    for line in file:
        print(line.strip())

• Read specific characters:

with open("example.txt", "r") as file:
    print(file.read(10))  # Reads first 10 characters

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3. Writing to Files

• Write new content (overwrites existing file):

with open("example.txt", "w") as file:
    file.write("Hello, Python File Handling!")

• Append content to existing file:

with open("example.txt", "a") as file:
    file.write("\nThis is appended text.")

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4. Using with Statement

The with statement automatically closes the file, even if an error occurs:

with open("example.txt", "r") as file:
    data = file.read()
    print(data)
# File is automatically closed here

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5. Handling CSV Files

Python provides csv module to handle CSV files:

import csv

# Writing to a CSV
with open("data.csv", "w", newline="") as file:
    writer = csv.writer(file)
    writer.writerow(["Name", "Age", "City"])
    writer.writerow(["Alice", 25, "New York"])
    writer.writerow(["Bob", 30, "London"])

# Reading from a CSV
with open("data.csv", "r") as file:
    reader = csv.reader(file)
    for row in reader:
        print(row)

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6. Practice Exercises

1. Create a text file and write your favorite poem into it.
2. Read the text file line by line and print lines containing the word "Python".
3. Create a CSV file for your friends' names, age, and city, and read it using Python.
4. Append new data to the existing CSV file and verify it.

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Lesson 10: Python Modules and Libraries | Coding Class Series

Introduction

Welcome to Lesson 10!
In this lesson, we will learn about Python Modules and Libraries. These are essential for reusing code, extending Python functionality, and making development faster and easier.

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1. What is a Module?

A module is a Python file (.py) that contains functions, classes, and variables which you can use in other Python programs.

Example:

# math_module.py
def add(a, b):
    return a + b

def subtract(a, b):
    return a - b

You can use this module in another file using import:

import math_module

print(math_module.add(10, 5))       # Output: 15
print(math_module.subtract(10, 5))  # Output: 5

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2. Built-in Python Modules

Python has many built-in modules ready to use:

• math → Mathematical functions
• random → Random number generation
• datetime → Date and time functions
• os → Operating system functionalities

Example:

import math
import random
from datetime import datetime

print(math.sqrt(25))          # Output: 5.0
print(random.randint(1, 10))  # Output: Random number between 1 and 10
print(datetime.now())         # Output: Current date and time

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3. Installing Third-Party Libraries

Python libraries like requests, numpy, pandas, etc., can be installed using pip:

pip install requests
pip install numpy

Example using requests:

import requests

response = requests.get("https://api.github.com")
print(response.status_code)  # Output: 200

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4. Creating Your Own Library

You can combine multiple modules into a package (your own library):

my_library/
│
├── __init__.py
├── math_utils.py
└── string_utils.py

Usage:

from my_library.math_utils import add
print(add(5, 10))  # Output: 15

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5. Practice Exercises

1. Create a module calc.py with functions multiply and divide. Import it in another file and test it.
2. Use the random module to generate a random list of numbers and find the max and min.
3. Install requests and fetch data from any public API.
4. Create a simple package with 2 modules and use it in a program.

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Lesson 9: Object-Oriented Programming (OOP) in Python | Coding Class Series

Introduction

Welcome to Lesson 9!
In this lesson, we will learn Object-Oriented Programming (OOP) in Python, which is a powerful way to structure code using classes and objects. OOP helps you write reusable, organized, and maintainable programs.

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1. What is OOP?

Object-Oriented Programming (OOP) is a programming paradigm that uses objects to represent real-world entities.
Key concepts:

• Class → Blueprint of an object
• Object → Instance of a class
• Attributes → Properties of an object
• Methods → Functions of an object

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2. Creating a Class and Object

Example:

class Person:
    def __init__(self, name, age):
        self.name = name  # Attribute
        self.age = age    # Attribute

    def greet(self):
        print(f"Hello, my name is {self.name} and I am {self.age} years old.")

# Creating an object
person1 = Person("Alice", 20)
person1.greet()  # Output: Hello, my name is Alice and I am 20 years old.

Explanation:

• __init__ → Constructor method, runs automatically when object is created
• self → Refers to the current object

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3. Inheritance

Inheritance allows a class to reuse code from another class.

class Student(Person):
    def __init__(self, name, age, student_id):
        super().__init__(name, age)
        self.student_id = student_id

    def show_id(self):
        print(f"My student ID is {self.student_id}")

student1 = Student("Bob", 18, "S123")
student1.greet()      # Inherited method
student1.show_id()    # Own method

Benefits:

• Reuse existing code
• Create hierarchical relationships
• Simplify complex programs

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4. Encapsulation

Encapsulation is the concept of hiding private details of an object.

class BankAccount:
    def __init__(self, balance):
        self.__balance = balance  # Private attribute

    def deposit(self, amount):
        self.__balance += amount

    def get_balance(self):
        return self.__balance

account = BankAccount(1000)
account.deposit(500)
print(account.get_balance())  # Output: 1500

Note: Prefix __ to make an attribute private.

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5. Polymorphism

Polymorphism allows methods with the same name to behave differently depending on the object.

class Dog:
    def speak(self):
        print("Woof!")

class Cat:
    def speak(self):
        print("Meow!")

animals = [Dog(), Cat()]
for animal in animals:
    animal.speak()
# Output: Woof! Meow!

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6. Practice Exercises

1. Create a class Car with attributes brand and year, and method display_info().
2. Create a subclass ElectricCar that inherits from Car and adds battery_capacity.
3. Create objects of both classes and call their methods.
4. Make a class Account with private balance and methods deposit and withdraw.

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