Investigate Python dependency issues

[m-wcislo]

Fixes #118

Before merge following needs to be applied:

• [ ] At least one example testcase added in testcases/
• [ ] Library Documentation regenerated according to Generate docs
• [ ] PR entry added in CHANGELOG.md in In progress section
• [ ] All new testcases tagged as prerelease along other tags to exclude it from execution until released on PyPI
• [ ] Coverage threshold increased in .coveragerc if new coverage is higher than actual, see the lint-and-coverage step in CI

fail_under = 86