Description from the numexpr project page [1]:
> Numexpr is a fast numerical expression evaluator for NumPy. With it,
> expressions that operate on arrays (like "3*a+4*b") are accelerated and use
> less memory than doing the same calculation in Python.
I am adding it, because it is a dependency of the pytables package.
[1]: https://github.com/pydata/numexpr
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