Python/Basic Python Programs/Program

Find Largest of Three Numbers

Compare three numbers and print the largest one (or that some/all are equal).

PythonBeginner

What You'll Learn

  • •Chaining relational operators with and
  • •Extending comparison logic to three values
  • •Using elif branches to cover multiple conditions
Python
Try
# Program to find the largest of three numbers

a = float(input("Enter first number: "))
b = float(input("Enter second number: "))
c = float(input("Enter third number: "))

if a >= b and a >= c:
    largest = a
elif b >= a and b >= c:
    largest = b
else:
    largest = c

print("Largest number is:", largest)

Output

Enter first number: 10
Enter second number: 25
Enter third number: 7
Largest number is: 25.0

Find Largest of Three Numbers in Python

We extend the comparison logic to three numbers using a combination of >= and logical operators and.

Logical Operators

  • and - returns True if both conditions are True
  • or - returns True if at least one condition is True
  • not - reverses the boolean value

Comparison Strategy

We check:

  1. If a is greater than or equal to both b and c.
  2. Else if b is greater than or equal to both a and c.
  3. Otherwise, c must be the largest (or tied for largest).

This pattern generalizes the two-number comparison approach.

Program Logic

python
if a >= b and a >= c:
    largest = a
elif b >= a and b >= c:
    largest = b
else:
    largest = c

Key Takeaways

1
Use and to combine multiple conditions
2
>= handles equality cases automatically
3

This pattern can be extended to more numbers

4

Storing result in a variable makes code cleaner

Step-by-Step Breakdown

  1. 1Read three numbers from the user.
  2. 2Use if-elif-else with combined conditions to find the maximum.
  3. 3Store the result in a variable named largest.
  4. 4Print the largest value.
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Find Largest of Two Numbers
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Check Positive, Negative, or Zero