Boltons is a set of pure-Python utilities in the same spirit as — and yet conspicuously missing from — the standard library, including:

• Atomic file saving, bolted on with fileutils
• A highly-optimized OrderedMultiDict, in dictutils
• Two types of PriorityQueue, in queueutils
• Chunked and windowed iteration, in iterutils
• A full-featured TracebackInfo type, for representing stack traces, in tbutils
• A lightweight UTC timezone available in timeutils.
• Recursive mapping for nested data transforms, with remap