.. currentmodule:: playdoh

.. _example-map_dependencies:

Example: map_dependencies
=========================

Example usage of :func:`map` with a function that has module dependencies.

::

    from playdoh import *
    
    
    # Import an external module in the same folder
    from external_module import external_fun
    
    
    # The function to parallelize
    def fun(x):
        # Use the function defined in the external module
        return external_fun(x) ** 2
    
    # This line is required on Windows, any call to a Playdoh function
    # must be done after this line on this OS.
    # See http://docs.python.org/library/multiprocessing.html#windows
    if __name__ == '__main__':
        # Execute ``fun(1)`` and ``fun(2)`` in parallel on two CPUs on this machine
        # and return the result.
        # The ``codedependencies`` argument contains the list of external Python
        # modules
        # to transfer on the machines executing the task. It is only needed when
        # using
        # remote machines, and not when using CPUs on the local machine.
        print map(fun, [1, 2], codedependencies=['external_module.py'])