Guide to Reading the API Reference

The API documentation is auto-generated using sphinx and the napolean sphinx extension. Some of the layout and terminology may need some more explanation.

The documentation is now built with intersphinx which makes references to types from the Python standard library and most external packages clickable. So, for example, if you see a function with a type pd.DataFrame you can click on that and you will be taken to pandas documentation for the pandas DataFrame.

API Documentation Structure

The API listings are grouped by sub-package, then module, then class.

The class layout can appear a little confusing because of some limitations of the auto-documentation (or more likely some limitations of my knowledge of how to use it).

In particular, the documented public attributes of classes (actually, attributes of class instances) are included without a header section.

Class documentation is layed out in the following structure:

  • Class summary: the __init__ signature header
    • Attributes:

      Documented public attributes (other than explicit properties). The Attributes section has no title so everything you see until the instance creation documentation is an attribute.

    • Class instantiation:

      the __init__ signature and documentation, i.e. the syntax to create a new instance of this class.

    • Class methods and Class properties.

Type Annotations

The package uses type annotations with types imported from the typing library. For a full explanation of how these are used and how to interpret some of the odder-looking types please see PEP 484.

typing uses abstract classes to help deal with duck typing - e.g. MyFancyList may implement all required list interfaces but not actually be derived from list.

Most of the types used are easily interpretable (e.g. Tuple ~= tuple) with the advantage that you can supply type annotations to Tuple’s members - e.g. Tuple[str, int, float].

For all type annotations used from the Python typing module, you can click on the type in the API documentation to navigate to the Python docs official documentation.

Some members of typing commonly used in are a little more esoteric than List or Tuple:


An object supporting keyed access to its members (like a dict). E.g. Mapping[str, MyClass]: when this appears in a parameter type annotation, it means that any dict-like object (that takes a type str as a key and returns an object of type MyClass) T2 is acceptable. This is more rarely used in return type annotations but means that the returned object will support keyed access to members but not necessarily implement everything that dict supports.


An object that supports iterator interface. e.g. Iterable[int]


The specified type maybe present or None. e.g. Optional[str]: means that either str or None is accepted or returned.


More general form of Optional where multiple types are acceptable. e.g. Union[str, float]: means that either a str or a float is acceptable


Any type is acceptable.