Adding Docstrings

A docstring is a string literal that is used right after the definition of a module, function, class, or method. They are used to document our code. This page will give you a set of guidelines to write efficient and correct docstrings.

Formatting the Docstrings

Please begin the description of the class/function in the same line as the 3 quotes:

def do_this():
    """This is correct.

def dont_do_this():
    This is incorrect.

NumPy Format

The Manim Community uses numpy format for the documentation.

Use the numpy format for sections and formatting - see

This includes:

  1. The usage of Attributes to specify ALL ATTRIBUTES that a class can have and a brief (or long, if needed) description.

Also, __init__ parameters should be specified as Parameters on the class docstring, rather than under __init__. Note that this can be omitted if the parameters and the attributes are the same (i.e., dataclass) - priority should be given to the Attributes section, in this case, which must always be present, unless the class specifies no attributes at all. (See more on Parameters in number 2 of this list.)


class MyClass:
    """My cool class. Long or short (whatever is more appropriate) description here.

        The class's name.
        The class's id.
        The mobject linked to this instance. Defaults to `Mobject()` \
(is set to that if `None` is specified).

        The user's name.
        The user's id.
        The mobject linked to this instance.

    def __init__(name: str, id: int, singleton: MyClass, mobj: Mobject = None): ...
  1. The usage of Parameters on functions to specify how every parameter works and what it does. This should be excluded if the function has no parameters. Note that you should not specify the default value of the parameter on the type. On the documentation render, this is already specified on the function’s signature. If you need to indicate a further consequence of value omission or simply want to specify it on the docs, make sure to specify it in the parameter’s DESCRIPTION.

See an example on list item 4.


When documenting varargs (args and kwargs), make sure to document them by listing the possible types of each value specified, like this:

  The args specified can be either an int or a float.
  The kwargs specified can only be a float.

Note that, if the kwargs expect specific values, those can be specified in a section such as Other Parameters:

Other Parameters
  Parameter documentation here
  1. The usage of Returns to indicate what is the type of this function’s return value and what exactly it returns (i.e., a brief - or long, if needed - description of what this function returns). Can be omitted if the function does not explicitly return (i.e., always returns None because return is never specified, and it is very clear why this function does not return at all). In all other cases, it should be specified.

See an example on list item 4.

  1. The usage of Examples in order to specify an example of usage of a function is highly encouraged and, in general, should be specified for every function unless its usage is extremely obvious, which can be debatable. Even if it is, it’s always a good idea to add an example in order to give a better orientation to the documentation user. Use the following format for Python code:

    # python code here


Also, if this is a video- or animation-related change, please try to add an example GIF or video if possible for demonstration purposes.

Make sure to be as explicit as possible in your documentation. We all want the users to have an easier time using this library.


def my_function(
    thing: int,
    other: np.ndarray,
    name: str,
    d: "SomeClassFromFarAway",
    test: Optional[int] = 45
) -> "EpicClassInThisFile":  # typings are optional for now
    """My cool function. Builds and modifies an :class:`EpicClassInThisFile` instance with the given

        Specifies the index of life.
        Specifies something cool.
        Specifies my name.
        Sets thing D to this value.
        Defines the number of times things should be tested. \
    Defaults to 45, because that is almost the meaning of life.

        The generated EpicClass with the specified attributes and modifications.

    Normal usage::

        my_function(5, np.array([1, 2, 3]), "Chelovek", d=SomeClassFromFarAway(cool=True), test=5)
    # code...