boltons

Boltons is a collection of more than 230 BSD-licensed, pure-Python utilities intended to fill gaps in the Python standard library. The project describes itself as "like builtins, but boltons" and emphasizes that it relies on nothing beyond the standard library. Notable included constructs mentioned in the README include atomic file saving via fileutils, a highly optimized OrderedMultiDict in dictutils, two types of PriorityQueue in queueutils, chunked and windowed iteration in iterutils, recursive data structure iteration and merging through iterutils.remap, exponential backoff with jitter via iterutils.backoff, and a TracebackInfo type for representing stack traces in tbutils. Installation is available through pip (`pip install boltons`) and on macOS via MacPorts. Because the project is pure-Python with no dependencies, individual modules are independent and can be vendored or copied directly into a project if the full package is too large. The documentation includes an integration section describing this approach. The README notes that most boltons aim to be "good enough" for basic use cases, with advanced needs left to specialized third-party libraries. It also points readers to an architecture statement covering design philosophy and module organization, and invites feature requests or pull requests for missing functionality. Development setup uses uv, with commands provided for creating a virtual environment, installing the package in editable mode, and running the test suite (including doctests) through tox. The project states it is tested against Python 3.7 through 3.14 as well as PyPy3. Full documentation is hosted on Read the Docs, and a changelog is maintained in the repository.