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

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

.. _sphx_glr_auto_examples_example_class_decoration.py:


==============================================================================
Example: decorating specified methods of a custom class with custom decorators
==============================================================================

This example shows how to decorate methods of a custom class with custom
decorators.


.. code-block:: default

    import time

    from pydeco import Decorator, MethodsDecorator







Create timer decorator


.. code-block:: default



    class Timer(Decorator):
        """Timer decorator."""

        def __init__(self, *args, **kwargs):
            self.run = 0
            self.run_by_func = dict()
            self.total_runtime = 0
            Decorator.__init__(self, *args, **kwargs)

        def __repr__(self):
            """Return the string representation."""
            return ('Timer(run={}, run_by_func={}, total_runtime={:2.2f} ms)'
                    .format(self.run, self.run_by_func, self.total_runtime))

        def wrapper(self, instance, func, *args, **kwargs):
            """Wrap input instance method with runtime measurement."""
            # increment run attributes
            self.run += 1
            if func.__name__ not in self.run_by_func:
                self.run_by_func[func.__name__] = 1
            else:
                self.run_by_func[func.__name__] += 1

            # save current time
            ts = time.time()

            # call `func` on inputs
            outs = func(instance, *args, **kwargs)

            # compute elapsed time
            te = time.time()
            runtime = (te - ts) * 1000
            # Update total runtime of timer
            self.total_runtime += runtime

            print('[Log] runtime {!r} : {:2.2f} ms'.format(func.__name__, runtime))

            # return outputs of `func`
            return outs







Create custom decorators


.. code-block:: default



    class Decorator1(Decorator):
        """Decorator 1."""

        def __init__(self, *args, **kwargs):
            Decorator.__init__(self, *args, **kwargs)

        def wrapper(self, instance, func, *args, **kwargs):
            """Wrap input instance method with the herebelow code."""
            print('[Decorator 1] -> decorating {}.{}'.format(
                instance._Wrapper__wrapped_class.__name__, func.__name__))
            return func(instance, *args, **kwargs)


    class Decorator2(Decorator):
        """Decorator 2."""

        def __init__(self, *args, **kwargs):
            Decorator.__init__(self, *args, **kwargs)

        def wrapper(self, instance, func, *args, **kwargs):
            """Wrap input instance method with the herebelow code."""
            print('[Decorator 2] -> decorating {}.{}'.format(
                instance._Wrapper__wrapped_class.__name__, func.__name__))
            return func(instance, *args, **kwargs)







Create custom class


.. code-block:: default


    timer = Timer()


    class MyClass():
        """Custom class."""

        def __init__(self, *args, **kwargs):
            pass

        @timer
        def method_1(self, *args, **kwargs):
            print('Run method 1')

        @timer
        def method_2(self, *args, **kwargs):
            print('Run method 2')

        @timer
        def method_3(self, *args, **kwargs):
            print('Run method 3')







Test


.. code-block:: default


    # Without custom decorators
    # -----------------------------------------------------------------------------

    # instantiate the class
    instance = MyClass()

    # run methods
    instance.method_1()
    instance.method_2()
    instance.method_3()

    # With custom decorators for the respective methods
    # -----------------------------------------------------------------------------

    # decorate the class
    MyClass_deco = MethodsDecorator(
        mapping={
            Decorator1(): ['method_1', 'method_2'],
            Decorator2(): ['method_1', 'method_3']
        })(MyClass)

    # instantiate the class
    instance = MyClass_deco()

    # run methods
    instance.method_1()
    instance.method_2()
    instance.method_3()




.. rst-class:: sphx-glr-script-out

 Out:

 .. code-block:: none

    Run method 1
    [Log] runtime 'method_1' : 0.11 ms
    Run method 2
    [Log] runtime 'method_2' : 0.03 ms
    Run method 3
    [Log] runtime 'method_3' : 0.06 ms
    [Decorator 2] -> decorating MyClass.method_1
    [Decorator 1] -> decorating MyClass.method_1
    Run method 1
    [Log] runtime 'method_1' : 0.03 ms
    [Decorator 1] -> decorating MyClass.method_2
    Run method 2
    [Log] runtime 'method_2' : 0.08 ms
    [Decorator 2] -> decorating MyClass.method_3
    Run method 3
    [Log] runtime 'method_3' : 0.04 ms




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

   **Total running time of the script:** ( 0 minutes  0.022 seconds)


.. _sphx_glr_download_auto_examples_example_class_decoration.py:


.. only :: html

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



  .. container:: sphx-glr-download

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



  .. container:: sphx-glr-download

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


.. only:: html

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

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