.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        Click :ref:`here <sphx_glr_download_examples_apps_lightning_profiler.py>`     to download the full example code
    .. rst-class:: sphx-glr-example-title

    .. _sphx_glr_examples_apps_lightning_profiler.py:


Simple Logging Profiler
===========================

This is a simple profiler that's used as part of the trainer app example. This
logs the Lightning training stage durations a logger such as Tensorboard. This
output is used for HPO optimization with Ax.


.. code-block:: default


    import time
    from typing import Dict

    from pytorch_lightning.loggers.logger import Logger

    from pytorch_lightning.profilers.profiler import Profiler


    class SimpleLoggingProfiler(Profiler):
        """
        This profiler records the duration of actions (in seconds) and reports the
        mean duration of each action to the specified logger. Reported metrics are
        in the format `duration_<event>`.
        """

        def __init__(self, logger: Logger) -> None:
            super().__init__()

            self.current_actions: Dict[str, float] = {}
            self.logger = logger

        def start(self, action_name: str) -> None:
            if action_name in self.current_actions:
                raise ValueError(
                    f"Attempted to start {action_name} which has already started."
                )
            self.current_actions[action_name] = time.monotonic()

        def stop(self, action_name: str) -> None:
            end_time = time.monotonic()
            if action_name not in self.current_actions:
                raise ValueError(
                    f"Attempting to stop recording an action ({action_name}) which was never started."
                )
            start_time = self.current_actions.pop(action_name)
            duration = end_time - start_time
            self.logger.log_metrics({"duration_" + action_name: duration})

        def summary(self) -> str:
            return ""


    # sphinx_gallery_thumbnail_path = '_static/img/gallery-lib.png'


.. rst-class:: sphx-glr-timing

   **Total running time of the script:** ( 0 minutes  0.000 seconds)


.. _sphx_glr_download_examples_apps_lightning_profiler.py:


.. only :: html

 .. container:: sphx-glr-footer
    :class: sphx-glr-footer-example



  .. container:: sphx-glr-download sphx-glr-download-python

     :download:`Download Python source code: profiler.py <profiler.py>`



  .. container:: sphx-glr-download sphx-glr-download-jupyter

     :download:`Download Jupyter notebook: profiler.ipynb <profiler.ipynb>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_