Runtime inspection
Inspecting values during debugging or logging.
Python · Class
type
type() returns an object's runtime type, or creates a new type when called with three arguments. Its one-argument result generally matches the object's __class__.
How it works
Call type() with one argument to inspect an object's runtime type. With three arguments, it dynamically creates a new type from a name, base classes, and an attribute namespace; the one-argument form is generally equivalent to accessing object.__class__.
Syntax
type(object)
type(name, bases, dict)Parameters
| Name | Type | Description |
|---|---|---|
object | object | The object whose runtime type is requested; alternatively, the three-argument form accepts a name, base classes, and an attribute namespace for creating a type. |
Returns
With one argument, returns the object's type object; the three-argument form creates a new type.
Key points
- Use type(value) to obtain the runtime type of value.
- The result can be compared with a class object such as int or str.
- type() is available directly; no import is needed.
- A type object represents an object type and does not add special operations through type() itself.
Common mistakes
- For inspection, type() returns a type object; it is generally the same object available through object.__class__.
- The one-argument form reports an object's type rather than testing whether it belongs to a class hierarchy.
Example: Inspect an object's type
value = 42
print(type(value))
print(type(value) is int)Displays the runtime type of an integer and checks whether that type object is exactly int.
When to use it
Exact type checks
Comparing a value with an exact built-in class.
Dynamic class creation
Creating classes dynamically from a name, bases, and namespace.
Related
object.__class__isinstance()issubclass()types