* Fixed a memory issue (Python garbage collector gets too far behind) related to large basket recovery. * ROOT now splits the serialization of `std::map`; added handling of split key-value pairs. * Implemented TRef as a type that can be read from TTrees.
3.9.0
No change in code, but this is the first release to explicitly require awkward<1.0, so that when awkward 1.0 does come to exist, most uproot users won't accidentally upgrade to it. (PR 318)
To get awkward 1.0, users will need to explicitly upgrade to uproot 4.0.
3.8.2
uproot can now write ROOT files which have TTrees with empty TBaskets. Fixes bug preventing ROOT from adding objects to files created in uproot.
3.8.1
Histograms with bin labels can now be written by uproot into new ROOT files.
The checksum of lz4 compressed ROOT files is now checked when they are being read by uproot. xxhash is now a strict dependency for reading lz4 compressed ROOT files.
3.8.0
TTree.pandas.df` was broken by the rename of `awkward.index` to `awkward.localindex` (which itself was to resolve a name-collision). Calling `localindex` and updating the minimum awkward version to 0.12 fixes that problem. (PR 303)
3.7.2
Fixes 294 with 295: `uproot.pandas.iterate` assumes Python 3's absolute imports, so for Python 2 to work, we need
python from __future__ import absolute_import
at the top of every file in uproot. (Thanks, chrisburr!)