In Python, elif (short for "else if") is a control flow keyword used within conditional statements. It allows you to create a series of checks following an initial if statement. If the if condition is False, the program proceeds to evaluate the first elif condition. If that elif condition is True, its corresponding code block is executed, and the rest of the elif and else statements are skipped.
Structure:
elif structure
if condition1:
# Code to execute if condition1 is True
elif condition2:
# Code to execute if condition1 is False and condition2 is True
# ... (more elif statements can be added)
else:
# Code to execute if none of the above conditions are True
Points to Remember:
⮚ There can be zero or more elif statements after an if statement.
⮚ elif conditions are evaluated only if the preceding if and any previous elif conditions were False.
⮚ Only one elif block can be executed per conditional statement.
⮚ An else block is optional and executes if none of the if or elif conditions are True.
Examples:
Grade Evaluation
Finding grade by marks example using elif in python
score = 85
if score >= 90:
grade = "A"
elif score >= 80:
grade = "B"
elif score >= 70:
grade = "C"
else:
grade = "F"
print(f"Your grade is: {grade}")
Output
Your grade is: B
In this example, if score is 85, the first if condition (score >= 90) is False, so the program moves to the first elif. Since score >= 80 is True, the grade is assigned "B" and the rest of the elif and else statements are skipped.
Day of the Week
Finding day in week using elif in python
day = 3
if day == 1:
day_name = "Monday"
elif day == 2:
day_name = "Tuesday"
elif day == 3:
day_name = "Wednesday"
elif day == 4:
day_name = "Thursday"
elif day == 5:
day_name = "Friday"
elif day == 6:
day_name = "Saturdar"
elif day == 7:
day_name = "Sunday"
else:
day_name = "Invalid day number"
print(f"Today is: {day_name}")
Output
Today is: Wednesday
This code uses a chain of elif statements to map day numbers (1-7) to their corresponding day names. If day is not a valid number, the else block assigns "Invalid day number".
Discount Calculator (with Multiple elifs)
Calculating discount example using elif in python
amount = 100
discount_rate = 0.1 # 10% discount
if amount >= 200:
discount = amount * discount_rate
elif amount >= 150:
discount = 15 # Fixed discount for amounts between 150 and 200
elif amount >= 100:
discount = amount * 0.05 # 5% discount for amounts between 100 and 150
else:
discount = 0 # No discount for amounts less than 100
final_price = amount - discount
print(f"Final price after discount: {final_price}")
Output
Final price after discount: 95.0
This example demonstrates multiple elif conditions to apply different discount rates based on the purchase amount.
File Type Checker:
Checking file type example using if else in python
extension = "jpg"
if extension == "jpg" or extension == "jpeg":
print("jpg/jpeg Image file")
elif extension == "png":
print("PNG image file")
elif extension == "svg":
print("svg image file")
else:
print("Unknown file type")
Output
jpg/jpeg Image file
This code uses elif to check for specific file extensions (JPEG, PNG, SVG) and prints the corresponding file type message.
Leap Year Checker
Leap year or not example using if else in python
year = 2024
if year % 4 != 0:
print("Not a leap year")
elif year % 100 == 0 and year % 400 != 0:
print("Not a leap year (century year not divisible by 400)")
else:
print("Leap year")
Output
Leap year
In this example, elif is used to handle the special case of century years (divisible by 100) that are not leap years unless also divisible by 400.
When to Use elif:
When you have multiple conditions to check in a single decision-making block.
When you want to avoid nested if statements, which can make code harder to read and maintain.
When you have a specific order in which you want to evaluate conditions.
In Summary:
elif provides a concise and readable way to handle multiple conditions in Python's conditional statements. By chaining if and elif statements, you can create complex decision-making logic that executes the appropriate code based on the evaluated conditions.
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