Add 'mid' property to Interval class

[currocam]

Description

Add mid property to the Interval and Tree class, as requested in #2903

PR Checklist:

• [x] Tests that fully cover new/changed functionality.
• [x] Documentation including tutorial content if appropriate.
• [x] Changelogs, if there are API changes.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 89.72%. Comparing base (a0baaaf) to head (b023b11). Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #2960   +/-   ##
=======================================
  Coverage   89.72%   89.72%           
=======================================
  Files          29       29           
  Lines       31567    31573    +6     
  Branches     6113     6115    +2     
=======================================
+ Hits        28322    28328    +6     
  Misses       1853     1853           
  Partials     1392     1392           

Flag	Coverage Δ
c-tests	86.55% <ø> (ø)
lwt-tests	80.78% <ø> (ø)
python-c-tests	88.98% <ø> (ø)
python-tests	99.01% <100.00%> (+<0.01%)	:arrow_up:

Flags with carried forward coverage won't be shown. Click here to find out more.

Files with missing lines	Coverage Δ
python/tskit/trees.py	98.78% <100.00%> (+<0.01%)	:arrow_up:

[currocam]

ci/circleci: build-32 and codecov/project don't pass, but I don't know how those errors are related with my PR

[petrelharp]

Hm - well, there's currently just one test, but two methods added (although one calls the other). Perhaps add another test for the Interval property (so it is tested autonomously)? The CI failures might be just transient.

[currocam]

Hi, I just added the second test! Thank you for reviewing the changes

And for making such amazing piece of software! I've used a lot doing my master's thesis and I hope I will keep doing after I finish :)

[jeromekelleher]

Looks like you have a few lint issues that need to be fixed also.

[jeromekelleher]

Thanks @currocam! It's probably worth installing pre-commit, following the dev docs here. (pre-commit install, should do it).

It would be good to rebase and squash the commits also, as this is a small change. This guide may be helpful.

[currocam]

Hi! Thank you very much! I was in fact in the process of install pre-commit, thanks for pointing that out!

[jeromekelleher]

Great, looks ready to merge 👍

[benjeffery]

@mergifyio rebase

[mergify[bot]]

rebase

☑️ Nothing to do

• [ ] -conflict [📌 rebase requirement]
• [X] -closed [📌 rebase requirement]
• [X] queue-position=-1 [📌 rebase requirement]
• [X] any of:
  • [X] #commits-behind>0 [📌 rebase requirement]
  • [ ] #commits>1 [📌 rebase requirement]
  • [ ] -linear-history [📌 rebase requirement]