Difference between type() and isinstance()
Let's understand the difference between type() and isinstance() with the example code below.
class Polygon: def sides_no(self): pass class Triangle(Polygon): def area(self): pass obj_polygon = Polygon() obj_triangle = Triangle() print(type(obj_triangle) == Triangle) # true print(type(obj_triangle) == Polygon) # false print(isinstance(obj_polygon, Polygon)) # true print(isinstance(obj_triangle, Polygon)) # true
Output
True False True True
In the above example, we see that type()
cannot distinguish whether an instance of a class is somehow related to the base class. In our case, although obj_triangle
is an instance of child class Triangle
, it is inherited from the base class Polygon
. If you want to relate the object of a child class with the base class, you can achieve this with isinstance()
.