The easiest and most efficient way to subtract two numbers in Python is to use the minus (-) operator. Just use the (-) between the two numbers.

k = 21
b = 19

l = k - b

print(l)

# Output: 2

If the first number is greater than the second, the output will be positive. If it is vice versa, the output will be negative.

k = 21
b = 19

negative = b - k

print(negative)

# Output: -2

If both numbers are the same, the output will be 0.

kb = 19
kl = 19

zero = kb - kl

print(zero)

# Output: 0

Alternate ways

Here are three alternate ways:

1. Using operator.sub()
2. Using a lambda function
3. Using a custom function

Approach 1: Using an operator.sub()

Python provides a built-in module called “operator” that we can import and use its “sub()” method to subtract numbers.

import operator

first_num = 200
second_num = 143

output = operator.sub(first_num, second_num)

print(output)

# Output: 57

The operator.sub() method accepts the two numbers for subtraction and returns the output. It is no brainer!

Approach 2: Using a lambda function

Without having a full-fledged function, we can create a lambda function, also known as an anonymous (unnamed) function. It will accept two variables to subtract and return the result.

Here is the one-liner:

print((lambda x, y: x - y)(100, 50))

# Output: 50

In this code, lambda x, y: x-y defines an anonymous function that subtracts y from x. So, 100 – 50 = 50.

Approach 3: Using a custom function

You can think of a custom function as a reusable logic that you can use in multiple places, making your code more organized.

In our case, you can define a subtraction logic in the custom function and call it however you want.

def subtraction(m, n):
    return m - n


calculation_1 = subtraction(5, 4)

print(calculation_1)
# Output: 1

calculation_2 = subtraction(5, 5)

print(calculation_2)
# Output: 0

calculation_3 = subtraction(5, 6)

print(calculation_3)
# Output: -1

Here, we called a custom function “subtraction()” three times, each with different values, and each time, it returned a different output.

Krunal Lathiya

With a career spanning over eight years in the field of Computer Science, Krunal’s expertise is rooted in a solid foundation of hands-on experience, complemented by a continuous pursuit of knowledge.