Python issubclass()

The issubclass() function checks if the object argument (first argument) is a subclass of classinfo class (second argument).

The syntax of issubclass() is:

issubclass(object, classinfo)

issubclass() Parameters

The issubclass() takes two parameters:

  • object - class to be checked
  • classinfo - class, type, or tuple of classes and types

Return Value from issubclass()

The issubclass() returns:

  • True if object is subclass of a class, or any element of the tuple
  • False otherwise

Example: How issubclass() works?

class Polygon:
  def __init__(polygonType):
    print('Polygon is a ', polygonType)

class Triangle(Polygon):
  def __init__(self):
    Polygon.__init__('triangle')
    
print(issubclass(Triangle, Polygon))
print(issubclass(Triangle, list))
print(issubclass(Triangle, (list, Polygon)))
print(issubclass(Polygon, (list, Polygon)))

When you run the program, the output will be:

True
False
True
True

It's important to note that class is considered a subclass of itself.