types — names for built-in types

This module defines names for some object types that are used by the standard Python interpreter but are not exposed as builtins (such as the type of functions or generators), together with a small number of helpers for dynamic class construction.

This is a MicroPython port of a subset of CPython’s types module. Several type aliases that have no useful representation in MicroPython (CodeType, MappingProxyType, SimpleNamespace, TracebackType, FrameType, GetSetDescriptorType, MemberDescriptorType) are exposed as None placeholders so that code which only references them keeps importing, but they will not match any real object via isinstance().

Availability: This module is part of micropython-lib. It is included by default only on the OpenMV N6 and OpenMV AE3. On the other OpenMV Cams it can be installed with mip (or frozen into a custom firmware); see Package management.

Type aliases

types.FunctionType: type

The type of user-defined functions and of objects created by def statements.

types.LambdaType: type

The type of lambda expressions. Identical to FunctionType.

types.GeneratorType: type

The type of generator-iterator objects produced by generator functions.

types.MethodType: type

The type of bound methods of user-defined class instances.

types.BuiltinFunctionType: type

The type of built-in functions such as len() and sys.exit().

types.BuiltinMethodType: type

The type of bound methods of built-in types (for example [].append). Identical to BuiltinFunctionType.

types.ModuleType: type

The type of imported modules.

types.CodeType: None

Placeholder for the CPython code object type. Always None in this implementation.

types.MappingProxyType: None

Placeholder for the read-only mapping proxy type returned by type.__dict__ in CPython. Always None in this implementation.

types.SimpleNamespace: None

Placeholder for the CPython types.SimpleNamespace class. Always None in this implementation.

types.TracebackType: None

Placeholder for the type of traceback objects. Always None in this implementation.

types.FrameType: None

Placeholder for the type of frame objects. Always None in this implementation.

types.GetSetDescriptorType: None

Placeholder for the type of attribute descriptors defined by extension types. Always None in this implementation.

types.MemberDescriptorType: None

Placeholder for the type of slot descriptors defined by extension types. Always None in this implementation.

Functions

types.new_class(name: str, bases: tuple = (), kwds: dict | None = None, exec_body: Callable[[dict], None] | None = None) → type

Create a class object dynamically in a way that mirrors the PEP 3115-compliant class statement.

  • name is the name of the new class.

  • bases is a tuple of base classes.

  • kwds is a dict of keyword arguments to pass to the metaclass. A "metaclass" key, if present, selects the metaclass directly.

  • exec_body is an optional callable that will be invoked with the freshly prepared class namespace; it should populate it with the new class’s attributes.

Returns the newly constructed class.

types.prepare_class(name: str, bases: tuple = (), kwds: dict | None = None) → tuple[type, dict, dict]

Compute the appropriate metaclass and prepare the namespace for a new class.

  • name is the name of the class about to be created.

  • bases is a tuple of base classes.

  • kwds is a dict of keyword arguments. A "metaclass" key, if present, is removed from the returned kwds and used as the metaclass. Otherwise the metaclass of bases[0] is used, falling back to type.

Returns a 3-tuple (metaclass, namespace, kwds) where namespace is the result of calling metaclass.__prepare__ if defined, or an empty dict otherwise, and kwds is a copy of the input with any "metaclass" entry removed.