coverage.py can be used to test code coverage by tests. Codecov shows coverage reports for the repository and for PRs. Either one of them or both may be useful tools to check whether code is being covered by tests.
Of course it is not a substitute for good unit test design, simply covering code by a unit test doesn't mean that the testing is thorough, but it could be useful to see that it is tested, at least.
coverage.py can be used to test code coverage by tests. Codecov shows coverage reports for the repository and for PRs. Either one of them or both may be useful tools to check whether code is being covered by tests.
Of course it is not a substitute for good unit test design, simply covering code by a unit test doesn't mean that the testing is thorough, but it could be useful to see that it is tested, at least.