__sub__ — Easy Examples

Defines behavior for the - subtraction operator

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Implementing __sub__

Basic implementation of __sub__ in a class.

python
class Example:
    def __sub__(self):
        return "Example __sub__"

obj = Example()
print(obj)

__sub__ defines behavior for the - subtraction operator. Implementing it lets you customize how Python interacts with your objects.

__sub__ in action

Seeing __sub__ called by Python's built-in operations.

python
# How Python calls __sub__ automatically
class Demo:
    def __init__(self, value):
        self.value = value

    def __sub__(self, other):
        print(f"__sub__ was called!")
        return self

d = Demo(42)
# This triggers __sub__:
result = d - Demo(1)

Python automatically calls __sub__ when you use the corresponding operator or function on your object.

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