Improve primelib.py test coverage #9943 (#10251)

* Update the doctest of primelib.py

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* Correct errors for the doctest of primelib.py

* last error for the doctest of primelib.py

* last error for the doctest of primelib.py

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Christian Clauss <[email protected]>