Conditional statements allow you to make decisions in your Python programs based on certain conditions. The most common conditional statements in Python are if, else, and elif (short for "else if").
# Using if statement
age = 18
if age >= 18:
print("You are an adult.")
# Using if-else statement
score = 85
if score >= 60:
print("Congratulations! You passed.")
else:
print("Unfortunately, you didn't pass.")
# Using if-elif-else statement
num = 7
if num > 0:
print("Positive")
elif num < 0:
print("Negative")
else:
print("Zero")
In Python, the blocks of code within the conditional statements are defined by indentation, not curly braces as in some other programming languages. Additionally, the colon (:) at the end of the if, else, and elif lines indicate the beginning of a new block of code.
You can also nest conditional statements inside each other to create more complex decision-making logic.
# Nested if-else statement
age = 22
if age >= 18:
print("You are an adult.")
if age >= 21:
print("You can legally drink.")
else:
print("You cannot legally drink.")
else:
print("You are a minor.")
# Nested if-elif-else statement
num = -5
if num > 0:
print("Positive")
elif num < 0:
print("Negative")
if num % 2 == 0:
print("Even")
else:
print("Odd")
else:
print("Zero")
Understanding conditional statements is fundamental to creating dynamic and responsive Python programs that can adapt to different situations and conditions.