Python: Improve performance of submodule name computation.
Python: Improve performance of submodule name computation.

github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql,github/codeql