09.-Python---Conditional-Statements-in-Python

Below is a detailed write-up for Conditional Statements (if, elif, else) in Python,

Python Course: Conditional Statements (if, elif, else)

Welcome to the Conditional Statements chapter of the Python Course repository. This chapter explains how to use if, elif, and else statements in Python, with explanations, examples, and exercises.

---

Overview

Topic	Description
Introduction	Explanation of conditional statements and their importance.
Syntax	Syntax and structure of if, elif, and else statements.
Key Points	Essential rules and notes about conditional statements.
Examples	Practical examples demonstrating different types of conditions.
Practice	Exercises to test your understanding of conditional statements.
Errors	Common mistakes and debugging tips for conditional statements.
Full Program	A complete program combining the learned concepts.
How to Run	Steps to clone and execute the code in this repository.

---

1. Introduction

Conditional statements control the flow of a program by executing code blocks based on conditions. They are essential for:

• Decision-making.
• Implementing logical operations.
• Controlling the sequence of execution.

---

2. Syntax

Statement	Description	Example
if	Executes the block if the condition is True.	if x > 0: print("Positive")
elif	Checks another condition if the first is False.	elif x == 0: print("Zero")
else	Executes if all conditions are False.	else: print("Negative")

---

3. Key Points

Rule	Explanation
Indentation	Indentation is mandatory to define code blocks.
Comparison Operators	Use ==, !=, <, >, <=, >= to compare values.
Logical Operators	Combine conditions using and, or, not.
Colon (:)	Every if, elif, or else statement must end with a colon.

---

4. Examples

Example	Code	Output
Basic if	if x > 0: print("Positive")	Positive
if-elif-else	if x > 0: print("Positive") elif x == 0: print("Zero") else: print("Negative")	Based on x value
Nested Conditions	if x > 0: if x % 2 == 0: print("Positive even") else: print("Positive odd")	Varies by x value
Logical Conditions	if x > 0 and x % 2 == 0: print("Positive even")	Based on conditions

---

5. Practice Exercises

Exercise Number	Description	Hint
1	Check if a number is positive, negative, or zero.	Use if-elif-else.
2	Implement a grading system based on a score.	Use if score >= 90 as the base.
3	Check if a year is a leap year.	Use if year % 4 == 0.

---

6. Common Errors

Error Type	Cause	Solution
IndentationError	Missing or incorrect indentation.	Use consistent indentation (4 spaces).
SyntaxError	Missing colon (:) after if, elif, or else.	Ensure all statements end with a colon.
TypeError	Comparing incompatible data types.	Validate inputs before comparison.

---

7. Full Program Example

# Age group classifier
age = int(input("Enter your age: "))

if age < 0:
    print("Invalid age!")
elif age <= 12:
    print("Child")
elif age <= 19:
    print("Teenager")
elif age <= 59:
    print("Adult")
else:
    print("Senior Citizen")




### **How to Use**

1. Save the above content as `README.md` in your **Conditional Statements** folder.
2. Pair it with example code files like `conditional_statements.py` and the practice exercise files.
3. Commit and push to GitHub with proper formatting.

Let me know if you need help with file structure or Git commands!