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Python Program to Find the Largest of Three Numbers

Beginner · Basics · CBSE class 11 practical list

This program finds the largest and the smallest of three numbers. It keeps a running answer and updates it whenever a bigger or smaller number turns up, the same idea used for longer lists.

Program

largest_of_three_numbers.py
a = 12 # or: a = int(input("Enter the first number: "))
b = 47 # or: b = int(input("Enter the second number: "))
c = 30 # or: c = int(input("Enter the third number: "))
largest = a
if b > largest:
largest = b
if c > largest:
largest = c
smallest = a
if b < smallest:
smallest = b
if c < smallest:
smallest = c
print("Numbers:", a, b, c)
print("Largest number:", largest)
print("Smallest number:", smallest)
Output
Numbers: 12 47 30
Largest number: 47
Smallest number: 12

How it works

  1. The program starts by assuming the first number, a, is the largest and stores it in largest.
  2. It then compares b and c with largest and replaces it whenever one of them is bigger.
  3. The smallest number is found the same way, with < instead of >.
  4. Because each comparison updates one variable, the same approach works for any number of values.

Other ways to write it

Using if-elif with and

Using if-elif with and
a, b, c = 12, 47, 30
if a >= b and a >= c:
largest = a
elif b >= a and b >= c:
largest = b
else:
largest = c
print("Largest of", a, b, c, "is", largest)
Output
Largest of 12 47 30 is 47

Each condition checks one number against both of the others, and >= makes sure equal numbers still give an answer.

Using max() and min()

Using max() and min()
a, b, c = 12, 47, 30
print("Largest number:", max(a, b, c))
print("Smallest number:", min(a, b, c))
Output
Largest number: 47
Smallest number: 12

max() and min() accept any number of values, so this is the shortest way to write it.

Try it yourself

Add a fourth number d and update the program so it still finds the largest and the smallest.

Edit the program above and press Run, or open it in the full editor to save it and share it. To watch it run line by line, open it in the visualizer.

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