Adding Typings#

Warning

This section is still a work in progress.

Adding type hints to functions and parameters#

Manim is currently in the process of adding type hints into the library. In this section, you will find information about the standards used and some general guidelines.

If you’ve never used type hints before, this is a good place to get started: https://realpython.com/python-type-checking/#hello-types.

Typing standards#

Manim uses mypy to type check its codebase. You will find a list of configuration values in the mypy.ini configuration file.

To be able to use the newest typing features not available in the lowest supported Python version, make use of typing_extensions.

To be able to use the new Union syntax (|) and builtins subscripting, use the from __future__ import annotations import.

Typing guidelines#

  • Manim has a dedicated typing module where type aliases are provided. Most of them may seem redundant, in particular the ones related to numpy. This is in anticipation of the support for shape type hinting (related issue). Besides the pending shape support, using the correct type aliases will help users understand which shape should be used.

  • Always use a type hint of None for functions that does not return a value (this also applies to __init__), e.g.:

def height(self, value) -> None:
    self.scale_to_fit_height(value)

  • For variables representing paths, use the StrPath or StrOrBytesPath type alias defined in the typing module.

  • *args and **kwargs shouldn’t be left untyped (in most cases you can use Any).

  • Following PEP 484, use float instead of int | float.

  • Mobjects have the typehint Mobject, e.g.:

def match_color(self, mobject: "Mobject"):
    """Match the color with the color of another :class:`~.Mobject`."""
    return self.set_color(mobject.get_color())

  • Always parametrize generics (list[int] instead of list, type[Any] instead of type, etc.). This also applies to callables:

rate_func: Callable[[float], float] = lambda t: smooth(1 - t)

Missing Sections for typehints are:#