Require types-python-dateutil

[tbekolay]

Pull Request Checklist

• 🧪 Added tests for changed code.
• 🛠️ All tests pass when run locally (run tox or make test to find out!).
• 🧹 All linting checks pass when run locally (run tox -e lint or make lint to find out!).
• 📚 Updated documentation for changed code.
• ⏩ Code is up-to-date with the master branch.

tox passes, but when I run tox -e lint I get a number of ANN401 Dynamically typed expressions errors.

I'm happy to add a test for the change but it's sort of unclear how to do this since it isn't a runtime change, it's a change that should only be picked up when running mypy. A short snippet that will raise an error without installing types-python-dateutil is:

(arrow.now() - arrow.now()).total_seconds()

Description of Changes

Not having types-python-dateutil installed results in confusing errors when running mypy on the subtraction of two Arrow instances. See python/mypy#11613 for a description of the issue, as well as some debugging from a few people.

[codecov]

Codecov Report

Merging #1102 (40aa9ea) into master (f8f3068) will not change coverage.
The diff coverage is n/a.

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[krisfremen]

@anishnya @jadchaar @systemcatch

would setup.py be the best place to put this?
or maybe the requirements files would be a better place?

[tbekolay]

or maybe the requirements files would be a better place?

The requirements file does not get used when installing arrow through normal means like pip install arrow, so putting it there would not fix the issue I reference in the PR description.

[jadchaar]

Hi all thanks for the contribution here. Given that this PR now has conflicts, I have made the change in 3a6cd95. Thanks a ton for raising this @tbekolay

[tbekolay]

Awesome thanks @jadchaar!