# UHI: Universal Histogram Interface

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This is a package meant primarily for [documenting][rtd-link] histogram
indexing and the PlottableHistogram Protocol and any future cross-library
standards. It also contains the code for the PlottableHistogram Protocol, to be
used in type checking libraries wanting to conform to the protocol. Eventually,
it might gain a set of tools for testing conformance to UHI indexing, as well.
It is not usually a runtime dependency, but only a type checking, testing,
and/or docs dependency in support of other libraries (such as
[boost-histogram][] 0.13+, [hist][] 2.1+, [mplhep][] 0.2.15+, [uproot][] 4+,
and [histoprint][] 2+).  There are a few useful runtime usable components
(listed below). Older versions are available for Python 3.6+. [See what's
new](https://github.com/scikit-hep/uhi/releases).

To assist plotting libraries in accepting Histograms from classic sources, see
`uhi.numpy_plottable.ensure_plottable_histogram`, which will adapt NumPy style
tuples into a simple PlottableHistogram.

The Protocols provided do support runtime checking, so
`isinstance(h, uhi.typing.plotting.PlottableHistogram)` is valid at runtime and
might be simpler than manually checking for the expected methods.

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[boost-histogram]:          https://github.com/scikit-hep/boost-histogram
[hist]:                     https://github.com/scikit-hep/hist
[mplhep]:                   https://github.com/scikit-hep/mplhep
[uproot]:                   https://github.com/scikit-hep/uproot4
[histoprint]:               https://github.com/scikit-hep/histoprint
