coalescing 0.1.1

This module is intended to ease access to nested data structures—in any combination of key or attribue access to each level of a hierarchy—where many paths in the tree may be missing. Typically, such data is encountered in semi-structured formats like JSON, YAML, or some XML, that is deserialized into Python data structures.

PEP 505 attempts to address this need with the addition of a number of new syntactic operators for attribute or item access where a special type of failure mode “coalesces” None values. Other libraries such as PyMaybe (https://pymaybe.readthedocs.io) perform a similar operation, and are more mature and robust.

On the other hand, by utilizing wrapt.ObjectProxy, this simple module manages to do some pretty neat stuff that even PyMaybe does not.

In this library, I simply want to provide simple wrapper classes that provide both what I think is more useful behavior and behavior that is semantically equivalent to PEP 505.

Classes:

GreedyAccess:

Wrap an object so that nested attribute and item access simply does not fail, but propagates a wrapped object across such nested access.

NullCoalesce:

Wrap an object so that encountering a None (or other indicated sentinel) at any level stops accessing further attributes and unboxes as a None (or other sentinel).

Aliased as NoneCoalesce