become PEP8 compliant

In #475, it was discovered that the flake8 linter action that had been running on PRs was outdated and therefore failing to post comments on PRs where PEP8 standards weren't met. Subsequent PRs are being used as an opportunity to come into compliance by making the needed edits on any files changed within that PR. However, a large number of changes are still required (primarily related to line length). For the sake of progress, #475 will be set to have a successful exit status even though there are errors (i.e. so the GitHub action passes), and maintainers/contributors are asked to take note of and address noncompliance moving forward. This issue documents the need for some intentional work towards meeting the standard.