Conditional Statements in Python

Introduction

Conditional statements in Python are essential for directing the flow of a program based on specific conditions. They enable the execution of certain code blocks when particular criteria are met, allowing for dynamic and responsive programming.

The if Statement

The if statement is the most basic form of a conditional statement in Python. It evaluates a condition, and if the condition is true, the indented block of code that follows is executed.

age = 20
if age >= 18:
    print("Eligible to vote.")

Output:

Eligible to vote.

Short-Hand if

Python allows for a more concise syntax when writing simple if statements, known as short-hand if.

age = 19
if age > 18: print("Eligible to vote.")

Output:

Eligible to vote.

The if-else Statement

The if-else statement provides an alternative path of execution when the if condition evaluates to false.

age = 10
if age <= 12:
    print("Travel for free.")
else:
    print("Pay for ticket.")

Output:

Travel for free.

Short-Hand if-else (Ternary Operator)

For simple conditional assignments or expressions, Python offers a compact syntax known as the ternary operator.

marks = 45
result = "Pass" if marks >= 40 else "Fail"
print(f"Result: {result}")

Output:

Result: Pass

The if-elif-else Statement

When multiple conditions need to be evaluated, the if-elif-else statement is used. It checks each condition in sequence and executes the corresponding block for the first true condition.

age = 25
if age <= 12:
    print("Child.")
elif age <= 19:
    print("Teenager.")
elif age <= 35:
    print("Young adult.")
else:
    print("Adult.")

Output:

Young adult.

Nested if Statements

Python allows for if statements to be nested within other if statements, enabling the evaluation of multiple layers of conditions.

age = 70
is_member = True
if age >= 60:
    if is_member:
        print("30% senior discount!")
    else:
        print("20% senior discount.")
else:
    print("Not eligible for a senior discount.")

Output:

30% senior discount!

Conclusion

Mastering conditional statements in Python is crucial for controlling the flow of programs and making decisions based on varying conditions. They form the backbone of logical operations and are indispensable in writing efficient and effective Python code.