Subtraction Operator in Python (-)

The Subtraction Operator (-) is a binary operator used to subtract the second operand from the first. In Python, it is versatile enough to handle simple integers, decimal numbers, and even complex mathematical values.

1. Basic Numeric Subtraction

Python performs subtraction between integers and floats with ease. When you subtract a float from an integer, the result is automatically converted to a float.

# Subtracting Integers
print(20 - 5)      # Output: 15

# Subtracting Floats
print(10.5 - 4.5)  # Output: 6.0

# Mixed types
print(10 - 2.5)    # Output: 7.5

2. Complex Number Subtraction

Just like addition, you can subtract complex numbers. Python subtracts the real parts and the imaginary parts separately.

c1 = 5 + 8j
c2 = 2 + 3j

print(c1 - c2)    # Output: (3+5j)

3. Set Difference

A unique feature of the - operator in Python is its use with **Sets**. It returns a new set containing elements that are in the first set but NOT in the second set.

set_a = {1, 2, 3, 4}
set_b = {3, 4, 5, 6}

# Elements in A but not in B
print(set_a - set_b)  # Output: {1, 2}

4. Strings

With string operand, the subtraction operation throws a TypeError (unsupported operand type). The following errors may be observed if any one operand is of type string.

5. Common Errors To Avoid

# "Hello" - "H"    # Raises TypeError
# [1, 2] - [1]     # Raises TypeError