def convert_py_to_cpp_namespace(python_namespace: str) -> str:
    """Convert a Python namespace name to a C++ namespace.

    Parameters
    ----------
    python_namespace : `str`
        A string describing a Python namespace. For example,
        ``'lsst.example'``.

    Returns
    -------
    cpp_namespace : `str`
        A C++ namespace. For example: ``'lsst::example'``.
    """
    return python_namespace.replace(".", "::")