When using .. runpython:: with :rst:, any stderr output (deprecation warnings, etc.) causes [runpythonerror] to be literally appended to the RST content and rendered into the final documentation. There was no way to suppress this.

Changes

• New :hide_err: flag option on RunPythonDirective — when present, skips appending the \n[runpythonerror]\n<stderr> block to the output content
• Docstring updated to document the new option alongside existing ones
• New test test_runpython_hide_err verifying the error block is suppressed while stdout is preserved

Usage

.. runpython::
    :rst:
    :hide_err:

    import warnings
    warnings.warn("deprecated", DeprecationWarning)
    print("This RST output still appears cleanly")

Without :hide_err:, the DeprecationWarning would render as [runpythonerror] followed by the warning text in the output.