The ``startup_code.py`` module
==============================

.. py:module:: ansys.lumerical.mcp.startup_code


Summary
-------








.. py:currentmodule:: startup_code
.. tab-set::









    .. tab-item:: Constants

        .. list-table::
          :header-rows: 0
          :widths: auto


          * - :py:obj:`~LUMERICAL_STARTUP_CODE`
            - 















Description
-----------

Bootstrap code fed into the framework's persistent Python subprocess.

The framework's :class:`PersistentPythonSession` pipes startup code into a
``python -u -i`` stdin, whose line-oriented parser treats a blank line at
column 0 as the end of a compound statement, so multi-line ``def``/``try``
blocks can't be sent directly. Instead, the real helpers live in the normal,
lint-friendly :mod:`ansys.lumerical.mcp._subprocess_helpers` module. Its
source is read, base64-encoded, and shipped as a two-line wrapper that decodes
and executes it. (``exec`` parses the whole string as a module, so blank lines
and docstrings work.)

:mod:`_subprocess_helpers` is **never imported in this parent process**.
Its source is only read via :mod:`importlib.resources`, keeping the parent
free of its import-time side effects (``matplotlib.use('Agg')`` and the
``ansys.lumerical.core`` probe) and letting the subprocess run without
``ansys.lumerical.mcp`` installed (only built-in :mod:`base64` is needed).

Seeded subprocess globals: ``FDTD``/``MODE``/``DEVICE``/``INTERCONNECT``
(from ``ansys.lumerical.core``), the ``_lumerical_sessions`` registry, and
the ``_lum_*`` helpers. (See :mod:`ansys.lumerical.mcp._subprocess_helpers`.)

..
    !! processed by numpydoc !!






Module detail
-------------

.. py:data:: LUMERICAL_STARTUP_CODE