Split core.py into two files in separate python package

[heyman]

I took a stab at the second part of #1328 and split locust.core into a separate locust.user package containing two moduels; locust.user.task and locust.user.users, as described here: #1328 (comment).

I also moved the wait_time, sequential_taskset and inspectlocust modules (which I renamed to inspectuser) into the locust.user package.

When moving/renaming files I took extra care to have separate commits that would only move/rename a file without any changes, so that we will get to keep as much git history as possible.

Here is the current structure of the locust.user package:

user/
  - __init__.py
  - task.py
    - get_tasks_from_base_classes  (needed by both LocustMeta and TaskSetMeta)
    - @task
    - TaskSetMeta
    - TaskSet
    - SequentialTaskSet
    - DefaultTaskSet
  - users.py
    - LocustMeta
    - Locust
    - HttpLocust
  - wait_time.py
  - sequential_taskset.py
  - inspectuser.py

Overall I think it makes a lot of sense to have a user package namespace, though I'm a bit split when it comes to having the two separate user.task and user.users modules, since their code is very related to each other. I guess an alternative would be to recreate this PR, but only moving core.py into the user package, instead of splitting it into task.py and users.py.

[codecov]

Codecov Report

Merging #1361 into master will increase coverage by 0.06%.
The diff coverage is 96.25%.

@@            Coverage Diff             @@
##           master    #1361      +/-   ##
==========================================
+ Coverage   80.70%   80.77%   +0.06%     
==========================================
  Files          24       26       +2     
  Lines        2254     2257       +3     
  Branches      345      344       -1     
==========================================
+ Hits         1819     1823       +4     
  Misses        343      343              
+ Partials       92       91       -1     

Impacted Files	Coverage Δ
locust/user/wait_time.py	100.00% <ø> (ø)
locust/user/users.py	95.58% <95.58%> (ø)
locust/contrib/fasthttp.py	85.85% <100.00%> (ø)
locust/main.py	19.59% <100.00%> (-0.41%)	⬇️
locust/user/__init__.py	100.00% <100.00%> (ø)
locust/user/inspectuser.py	72.72% <100.00%> (ø)
locust/user/sequential_taskset.py	85.18% <100.00%> (ø)
locust/user/task.py	96.00% <100.00%> (ø)
locust/util/deprecation.py	75.00% <100.00%> (ø)
... and 3 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 6f80d63...b911299. Read the comment docs.

[cyberw]

Lgtm! Im ok with splitting user/task into separate files, it doesnt matter that much. Git is actually quite good at recognizing a rename+changes unless the changes are too big.

Ok to merge.

[heyman]

Git is actually quite good at recognizing a rename+changes unless the changes are too big.

Oh, I thought it only worked if the file renames/moves were made without any other changes to the file that was moved. That info might be outdated though, and maybe that has improved?

[cyberw]

I dont know how small the changes need to be - Ive experienced it working and not working. Dont know if it has been improved :)

[cyberw]

You can see it before committing though

[heyman]

I dont know how small the changes need to be - Ive experienced it working and not working. Dont know if it has been improved :)

Ah! I guess doing a move/rename commit with no other changes should be super safe then :). Looking at the code for this PR, git does realise that user/task.py was previously core.py, but it hasn't kept the history for the lines of code that I moved out into user/users.py.

[cyberw]

Yea, I dont think git recognizes splitting a file in two.

[heyman]

Forgot to update documentation and docstrings for this PR. Fixed in 265a3bf.