Python Programming Tutorial

# Download Python from python.org
# For Windows: Download .exe installer
# For Mac: Download .pkg installer  
# For Linux: Use package manager

# Verify installation
python --version
# or
python3 --version

# Start Python shell
python

# Basic operations
>>> print("Hello, World!")
Hello, World!
>>> 2 + 3
5
>>> exit()

# hello.py
print("Hello, World!")
print("Welcome to Python Programming!")

# Run the program
python hello.py

# Variables (no declaration needed)
name = "John Doe"
age = 25
height = 5.9
is_student = True

# Multiple assignment
x, y, z = 1, 2, 3
a = b = c = 0

# Variable naming rules
# - Start with letter or underscore
# - Can contain letters, numbers, underscores
# - Case-sensitive
# - Cannot use Python keywords

# Single line comment

"""
Multi-line comment
or docstring
"""

'''
Another way to write
multi-line comments
'''

# Output
print("Hello, World!")
print("Name:", name, "Age:", age)
print(f"Hello, {name}! You are {age} years old.")

# Input
name = input("Enter your name: ")
age = int(input("Enter your age: "))
print(f"Hello, {name}!")

# List creation
fruits = ["apple", "banana", "orange"]
numbers = [1, 2, 3, 4, 5]
mixed = [1, "hello", 3.14, True]

# List operations
fruits.append("grape")        # Add to end
fruits.insert(0, "mango")    # Insert at index
fruits.remove("banana")      # Remove by value
popped = fruits.pop()         # Remove last
print(fruits[0])              # Access by index
print(fruits[-1])             # Last element
print(fruits[1:3])            # Slicing

# Dictionary creation
student = {
    "name": "John",
    "age": 20,
    "grade": "A"
}

# Dictionary operations
print(student["name"])        # Access value
student["email"] = "john@email.com"  # Add key-value
student.update({"city": "New York"}) # Update multiple
del student["age"]            # Delete key
print(student.keys())         # Get all keys
print(student.values())       # Get all values
print(student.items())        # Get key-value pairs

# Basic function
def greet():
    print("Hello, World!")

greet()  # Call function

# Function with parameters
def greet_person(name):
    print(f"Hello, {name}!")

greet_person("Alice")

# Function with return value
def add_numbers(a, b):
    return a + b

result = add_numbers(5, 3)
print(result)  # 8

# Default parameters
def greet(name, message="Hello"):
    print(f"{message}, {name}!")

greet("Bob")                    # Hello, Bob!
greet("Alice", "Hi")           # Hi, Alice!

# Variable arguments
def sum_all(*args):
    return sum(args)

print(sum_all(1, 2, 3, 4))     # 10

# Keyword arguments
def create_profile(**kwargs):
    for key, value in kwargs.items():
        print(f"{key}: {value}")

create_profile(name="John", age=25, city="NYC")

# Lambda (anonymous) functions
square = lambda x: x ** 2
print(square(5))  # 25

# Using with built-in functions
numbers = [1, 2, 3, 4, 5]
squared = list(map(lambda x: x**2, numbers))
print(squared)  # [1, 4, 9, 16, 25]

# Filter function
even_numbers = list(filter(lambda x: x % 2 == 0, numbers))
print(even_numbers)  # [2, 4]

# Class definition
class Student:
    # Class variable
    school = "SD Technology"
    
    # Constructor
    def __init__(self, name, age):
        self.name = name    # Instance variable
        self.age = age
        self.grades = []
    
    # Instance method
    def add_grade(self, grade):
        self.grades.append(grade)
    
    def get_average(self):
        if self.grades:
            return sum(self.grades) / len(self.grades)
        return 0
    
    # String representation
    def __str__(self):
        return f"Student: {self.name}, Age: {self.age}"

# Creating objects
student1 = Student("Alice", 20)
student2 = Student("Bob", 21)

# Using methods
student1.add_grade(85)
student1.add_grade(90)
print(student1.get_average())  # 87.5

# Parent class
class Person:
    def __init__(self, name, age):
        self.name = name
        self.age = age
    
    def introduce(self):
        print(f"Hi, I'm {self.name}")

# Child class
class Student(Person):
    def __init__(self, name, age, student_id):
        super().__init__(name, age)  # Call parent constructor
        self.student_id = student_id
    
    def study(self):
        print(f"{self.name} is studying")

# Using inheritance
student = Student("Alice", 20, "S001")
student.introduce()  # From parent class
student.study()      # From child class

# Writing to file
with open("data.txt", "w") as file:
    file.write("Hello, World!\n")
    file.write("Python File Handling")

# Reading from file
with open("data.txt", "r") as file:
    content = file.read()
    print(content)

# Reading line by line
with open("data.txt", "r") as file:
    for line in file:
        print(line.strip())

# Appending to file
with open("data.txt", "a") as file:
    file.write("\nNew line added")

# Working with CSV files
import csv

# Writing CSV
data = [["Name", "Age"], ["Alice", 25], ["Bob", 30]]
with open("people.csv", "w", newline="") as file:
    writer = csv.writer(file)
    writer.writerows(data)

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

# Install Flask: pip install flask

from flask import Flask, render_template, request

app = Flask(__name__)

@app.route('/')
def home():
    return "Hello, Flask!"

@app.route('/user/')
def user_profile(name):
    return f"Welcome, {name}!"

@app.route('/form', methods=['GET', 'POST'])
def form_handler():
    if request.method == 'POST':
        username = request.form['username']
        return f"Hello, {username}!"
    return '''
        

            
            
        
    '''

if __name__ == '__main__':
    app.run(debug=True)

# Install: pip install pandas numpy matplotlib

import pandas as pd
import numpy as np

# Creating DataFrame
data = {
    'Name': ['Alice', 'Bob', 'Charlie'],
    'Age': [25, 30, 35],
    'Salary': [50000, 60000, 70000]
}
df = pd.DataFrame(data)

# Basic operations
print(df.head())           # First 5 rows
print(df.info())           # DataFrame info
print(df.describe())       # Statistical summary

# Filtering data
young_employees = df[df['Age'] < 30]
print(young_employees)

# Reading from CSV
df = pd.read_csv('data.csv')

# Basic statistics
average_age = df['Age'].mean()
max_salary = df['Salary'].max()

import matplotlib.pyplot as plt

# Simple plot
x = [1, 2, 3, 4, 5]
y = [2, 4, 6, 8, 10]

plt.plot(x, y)
plt.xlabel('X-axis')
plt.ylabel('Y-axis')
plt.title('Simple Line Plot')
plt.show()

# Bar chart
categories = ['A', 'B', 'C', 'D']
values = [23, 45, 56, 78]

plt.bar(categories, values)
plt.title('Bar Chart')
plt.show()