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https://github.com/jlfwong/flask_debugtoolbar_lineprofilerpanel

Line Profiler Panel for Flask Debug Toolbar
https://github.com/jlfwong/flask_debugtoolbar_lineprofilerpanel

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Line Profiler Panel for Flask Debug Toolbar

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README 

        
Line Profile Panel for Flask Debug Toolbar

==========================================



.. image:: http://i.imgur.com/d5KaP.png



This is a panel for `flask_debugtoolbar`_ which enables the ability to view 

line profiling information from selected functions.



The line profile information comes from the `line_profiler`_ module, but you 

don't need to worry about that.



Installation

------------



First, you need to get the package. Install it with pip:



::



    pip install flask-debugtoolbar-lineprofilerpanel



Somewhere after you've set ``app.debug = True`` and before ``app.run``, you need

to specify the ``flask_debugtoolbar`` panels that you want to use and include

``'flask_debugtoolbar_lineprofilerpanel.panels.LineProfilerPanel'`` in that

list.



For example, here's a small flask app with the panel installed and with line 

profiling enabled for the `hello_world`:



::



    from flask import Flask

    app = Flask(__name__)



    import flask_debugtoolbar



    from flask_debugtoolbar_lineprofilerpanel.profile import line_profile



    @app.route('/')

    @line_profile

    def hello_world():

        return flask.render_template('hello_world.html')



    if __name__ == '__main__':

        app.debug = True



        # Specify the debug panels you want

        app.config['DEBUG_TB_PANELS'] = [

            'flask_debugtoolbar.panels.versions.VersionDebugPanel',

            'flask_debugtoolbar.panels.timer.TimerDebugPanel',

            'flask_debugtoolbar.panels.headers.HeaderDebugPanel',

            'flask_debugtoolbar.panels.request_vars.RequestVarsDebugPanel',

            'flask_debugtoolbar.panels.template.TemplateDebugPanel',

            'flask_debugtoolbar.panels.sqlalchemy.SQLAlchemyDebugPanel',

            'flask_debugtoolbar.panels.logger.LoggingPanel',

            'flask_debugtoolbar.panels.profiler.ProfilerDebugPanel',

            # Add the line profiling

            'flask_debugtoolbar_lineprofilerpanel.panels.LineProfilerPanel'

        ]

        toolbar = flask_debugtoolbar.DebugToolbarExtension(app)



        app.run()



Usage

-----



Unlike the regular profile panel that comes with ``flask_debugtoolbar``, the

line profiler will only profile functions you specifically tell it to. You can

either use it as a decorator or directly as a function.



::



    from flask_debugtoolbar_lineprofilerpanel.profile import line_profile



    # Using it as a decorator

    @app.route('/profile')

    @line_profile

    def profile_page():

        ...

        return flask.render_template('profile_page')



    # Explicit argument

    line_profile(some_function)



Note that if I had done ``line_profile(profile_page)`` in the example above, it

would've profiled the wrapper created by ``app.route``. In general, you probably

just want to use ``line_profile`` as a decorator.



Also note that the following will profile the decorator wrapper, not the inner

function.



::



    # Using it incorrectly as a decorator

    @line_profile

    @app.route('/profile')

    def profile_page():

        ...

        return flask.render_template('profile_page')



Always use ``@line_profile`` as the inner-most decorator.



.. _`flask_debugtoolbar`: https://github.com/mgood/flask-debugtoolbar

.. _`line_profiler`: https://github.com/certik/line_profiler



Using line_profiler with the Google AppEngine SDK

-------------------------------------------------



``line_profiler`` is implemented as a C extension.  Unfortunately, AppEngine does not support C extensions in the cloud, and ``dev_appserver`` simulates this restriction on your local machine.  If you'd like to use ``line_profiler`` on your local machine, you can monkey-patch the AppEngine SDK to permit it.  The Flask-DebugToolbar will make sure this plugin is disabled in production (it will catch any ImportErrors and disable the affected panel).



Simply open ``application/__init__.py``, which should look something like this::

    

    from __future__ import absolute_import



    from flask import Flask



    app = Flask('application')

    app.config.from_object('application.settings')



    if app.config['DEBUG']:

        from werkzeug.debug import DebuggedApplication

    

        app.wsgi_app = DebuggedApplication(app.wsgi_app, evalex=True)



        from flask.ext.debugtoolbar import DebugToolbarExtension

    

        toolbar = DebugToolbarExtension(app)



    import application.urls



and insert the monkey-patch, like so:



::



    from __future__ import absolute_import



    from flask import Flask



    app = Flask('application')

    app.config.from_object('application.settings')



    if app.config['DEBUG']:

        from werkzeug.debug import DebuggedApplication

    

        app.wsgi_app = DebuggedApplication(app.wsgi_app, evalex=True)



        # We can't use LineProfiler in production because it requires a C-extension,

        # but we can monkey-patch it in here for use on the dev server:

        try:

            import os, sys, re



            if 'SERVER_SOFTWARE' in os.environ and os.environ['SERVER_SOFTWARE'].startswith('Dev'):

                # white-list the line_profiler C extension

                sys.meta_path[3]._enabled_regexes.append(re.compile(r'.*line_profiler.*'))



                from flask_debugtoolbar_lineprofilerpanel.profile import line_profile



                ## import the methods you want to profile here, and whitelist them with line_profile:

                #from application.views import YourViewClass

                #

                #line_profile(YourViewClass.the_method_you_want_to_profile)

                #line_profile(YourViewClass.another_method_you_want_to_profile)

        except:

            pass

    



        # Make sure the monkey-patch is applied before you instantiate the DebugToolbarExtension.

        from flask.ext.debugtoolbar import DebugToolbarExtension

    

        toolbar = DebugToolbarExtension(app)



    import application.urls