Add support for reading TDatime

[veprbl]

No description provided.

[jpivarski]

Should this be linked in with

https://github.com/scikit-hep/uproot4/blob/c1c95c0ad6b6f1fe830ed7187a71420d5fff913b/src/uproot/_util.py#L814-L839

which convert ROOT's "datime" integers into Python datetime objects?

[veprbl]

Should this be linked in with

For sure, but in what way? Modify during read, or in Model.postprocess or add as a method?

[jpivarski]

For sure, but in what way? Modify during read, or in Model.postprocess or add as a method?

The canonical way would be to add a src/behaviors/TDatime.py containing a TDatime class and have this Model_TDatime inherit from that behavior. The behavior would then define a

    def to_datetime(self):
        return uproot._util.code_to_datetime(self._members["fDatime"])

method for Model_TDatime to inherit.

That's how the methods are usually named: histograms have to_numpy(), to_hist() (methods, not properties, to allow for future parameterization). The goal is not to rewrite the functionality of ROOT in Uproot, but to export objects to their Python equivalents (which generally provide the functionality of ROOT by themselves; for instance, datetime has all the methods for getting year, day, hours, isoformat, etc.).

[jpivarski]

scikit-hep-testdata 0.4.6 is now available. Tests that are looking for uproot-issue-407.root should find it.

[veprbl]

Could someone trigger the tests? I believe this is ready.

[jpivarski]

Sorry, I didn't realize that it was being held up.

[jpivarski]

Looks good to me! I'll set it to merge when the tests pass.