validator.py is a tool for ensuring that data conforms to certain sets of rules, called validations. A validation is essentially a schema for a dictionary, containing a list of rules for each key/value pair in the dictionary you want to validate. This is intended to fill a similar use case to form validations in WTForms or Rails, but for general sources of data, not just Web forms.
python-pptx is a pure Python library for manipulating Open XML PowerPoint files. It's useful for server-side generation of .pptx files on non-Windows server platforms, and also useful for utility purposes. It can round-trip any Open XML presentation (.pptx file) including all its elements, add slides, populate text placeholders (for example, to create a bullet slide), add an image to a slide with arbitrary position and size, add a textbox to a slide, and manipulate text font size and boldness.
Metakit is a small, portable database library using a hybrid relational / hierarchical data model with a column-wise internal storage format. For C++, include a single header file and 125 kb DLL or statically link directly. Ideal for desktops, embedded systems, smartphones, and PDAs. Bindings for Python and Tcl. A very mature, stable code base.