Python Programming Tutorial

 

Python is widely considered the best programming language for machine learning. It has gained immense popularity in the field of data science and machine learning.

• Python basics, Variables, Operators, Conditional Statements

1. Python Basics

# Print a message print("Welcome to Python Programming!")

Output:

Welcome to Python Programming!

2. Variables

# Variables are containers for storing data name = "Alice"      # String age = 25            # Integer height = 5.5        # Float is_student = True   # Boolean print(f"Name: {name}, Age: {age}, Height: {height}, Student: {is_student}")

Output:

Name: Alice, Age: 25, Height: 5.5, Student: True

3. Operators

# Arithmetic Operators x, y = 10, 3 print("Addition:", x + y) print("Division:", x / y) # Comparison Operators print("Is x greater than y?", x > y) # Logical Operators a, b = True, False print("a and b:", a and b) print("a or b:", a or b)

Output:

Addition: 13 Division: 3.3333333333333335 a and b: False a or b: True

4. Conditional Statements

age = 18 if age >= 18:     print("You are an adult.") elif 13 <= age < 18:     print("You are a teenager.") else:     print("You are a child.")

Output:

You are an adult.

• List and Strings

1. Lists

# Lists are mutable collections fruits = ["apple", "banana", "cherry"] print("Original List:", fruits) # Add, remove, and access elements fruits.append("orange") print("After Adding:", fruits) print("Second Fruit:", fruits[1])

Output:

Original List: ['apple', 'banana', 'cherry'] After Adding: ['apple', 'banana', 'cherry', 'orange'] Second Fruit: banana

2. Strings

# Strings are immutable sequences of characters greeting = "Hello, Python!" print("Uppercase:", greeting.upper()) print("Substring:", greeting[7:13])

Output:

Uppercase: HELLO, PYTHON! Substring: Python

• Dictionary, Tuple, Set

1. Dictionary

# Dictionary stores key-value pairs person = {"name": "Alice", "age": 25} print("Name:", person["name"]) person["age"] = 26  # Update print("Updated Dictionary:", person)

Output:

Name: Alice Updated Dictionary: {'name': 'Alice', 'age': 26}

2. Tuple

# Tuples are immutable colors = ("red", "green", "blue") print("First Color:", colors[0])

Output:

First Color: red

3. Set

# Sets are unordered collections of unique items numbers = {1, 2, 3, 3} print("Set:", numbers) numbers.add(4) print("After Adding:", numbers)

Output:

Set: {1, 2, 3} After Adding: {1, 2, 3, 4}

• While Loop, Nested Loops, Loop Else

1. While Loop

count = 0 while count < 5:     print("Count:", count)     count += 1

Output:

Count: 0 Count: 1 Count: 2 Count: 3 Count: 4

2. Nested Loops

for i in range(3):     for j in range(2):         print(f"i={i}, j={j}")

Output:

i=0, j=0 i=0, j=1 i=1, j=0 i=1, j=1 i=2, j=0 i=2, j=1

3. Loop Else

count = 3 while count > 0:     print(count)     count -= 1 else:     print("Countdown Finished!")

Output:

3 2 1 Countdown Finished!

• For Loop, Break, and Continue statements

1. For Loop

for i in range(5):     print("Number:", i)

Output:

Number: 0 Number: 1 Number: 2 Number: 3 Number: 4

2. Break Statement

for i in range(10):     if i == 5:         break     print("Number:", i)

Output:

Number: 0 Number: 1 Number: 2 Number: 3 Number: 4

3. Continue Statement

for i in range(10):     if i % 2 == 0:         continue     print("Odd Number:", i)

Output:

Odd Number: 1 Odd Number: 3 Odd Number: 5 Odd Number: 7 Odd Number: 9

• Functions, Return Statement, Recursion

1. Functions

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

Output:

Hello, Alice!

2. Recursion

def factorial(n):     if n == 1:         return 1     return n * factorial(n - 1) print("Factorial of 5:", factorial(5))

Output:

Factorial of 5: 120

• File Handling, Exception Handling

1. File Handling

# Write to a file with open("sample.txt", "w") as file:     file.write("Hello, File Handling!") # Read from a file with open("sample.txt", "r") as file:     content = file.read()     print("File Content:", content)

Output:

File Content: Hello, File Handling!

2. Exception Handling

try:     num = int(input("Enter a number: "))     print("Square:", num ** 2) except ValueError:     print("Invalid Input. Please enter a number.")

Input:

5

Output:

Enter a number: 5 Square: 25

• Object-Oriented Programming

class Person:     def __init__(self, name, age):         self.name = name         self.age = age     def greet(self):         return f"Hi, I'm {self.name} and I'm {self.age} years old." alice = Person("Alice", 25) print(alice.greet())

Output:

Hi, I'm Alice and I'm 25 years old.