Miscellaneous fixes: flake8 --select=E402,E731,E741,F821

[cclauss]

Fix six miscellaneous flake8 issues that formatters like psf/black will not auto-fix.

2     E402 module level import not at top of file
1     E731 do not assign a lambda expression, use a def
1     E741 ambiguous variable name 'l'
2     F821 undefined name 'get_service_uri'

[amacneil]

Can you add all the fixed checks to setup.cfg in these PRs so we can prevent future regressions?

[cclauss]

Let's just land these PRs and run psf/black and we will pass ALL flake8 tests.

[cclauss]

Adding them is going to mean that each PR has conflicts with all others because they are all modifying the same line.

[amacneil]

Adding them is going to mean that each PR has conflicts with all others because they are all modifying the same line.

I see, yes makes sense