issubclass()

Introspection

Returns True if a class is a subclass of another class.

Signature

issubclass(class, classinfo)

Returns

bool

Example

print(issubclass(bool, int))     # True
print(issubclass(str, object))   # True
print(issubclass(list, dict))    # False

About issubclass()

issubclass is a Python introspection function with the signature issubclass(class, classinfo). Returns True if a class is a subclass of another class. It returns a value of type bool.

Python provides a rich set of built-in functions and standard library modules that cover common programming tasks. Understanding these functions helps you write more idiomatic, efficient Python code. The issubclassfunction is commonly used in data processing, web development, scripting, and automation tasks.

When working with issubclass(), consider edge cases like empty inputs, None values, and type mismatches. Python's duck typing means many built-in functions work with any object that implements the required protocol (e.g., __len__ for len(), __iter__ for iteration). This flexibility is a key strength of Python's design philosophy.

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