Metadata-Version: 1.1
Name: gphoto2
Version: 0.9.0
Summary: Python interface to libgphoto2
Home-page: https://github.com/jim-easterbrook/python-gphoto2
Author: Jim Easterbrook
Author-email: jim@jim-easterbrook.me.uk
License: GNU GPL
Download-URL: https://github.com/jim-easterbrook/python-gphoto2/archive/gphoto2-0.9.0.tar.gz
Description: python-gphoto2
        ==============
        
        python-gphoto2 is a comprehensive Python interface (or binding) to `libgphoto2 <http://www.gphoto.org/proj/libgphoto2/>`_.
        It is built using `SWIG <http://swig.org/>`_ to automatically generate the interface code.
        This gives direct access to nearly all the libgphoto2 functions, but sometimes in a rather un-Pythonic manner.
        
        .. contents::
           :backlinks: top
        
        Dependencies
        ------------
        
        *   Python: http://python.org/ version 2.6 or greater (including Python 3)
        *   SWIG: http://swig.org/ version 2.0 or higher
        *   libgphoto2: http://www.gphoto.org/proj/libgphoto2/ version 2.4 or greater
        
        Note that you need the "development headers" versions of libgphoto2 and Python.
        Most Linux distributions' package managers have these, but the names vary.
        Look for ``libgphoto2-2-dev`` or ``libgphoto2-devel`` or something similar.
        
        Installation and testing
        ------------------------
        
        There are several ways to install python-gphoto2, with varying levels of control over the installation process.
        Note that they all need SWIG and the other dependencies - there are no "binary" packages at present.
        
        Install with ``pip``
        ^^^^^^^^^^^^^^^^^^^^
        
        The easiest installation method is to use the `pip <https://pip.pypa.io/>`_ command::
        
            sudo pip install gphoto2
        
        Install with ``git``
        ^^^^^^^^^^^^^^^^^^^^
        
        To install the very latest version, use `git <http://git-scm.com/>`_ to "clone" the GitHub repository, then change to the new directory::
        
            git clone https://github.com/jim-easterbrook/python-gphoto2.git
            cd python-gphoto2
        
        Python's `distutils <https://docs.python.org/2/library/distutils.html>`_ are used to build and install python-gphoto2::
        
            python setup.py build
            sudo python setup.py install
        
        Install a downloaded archive
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        
        Visit the `project releases page <https://github.com/jim-easterbrook/python-gphoto2/releases>`_ or `PyPI <https://pypi.python.org/pypi/gphoto2>`_ and download one of the zip or tar.gz files, then extract it and change to the new directory.
        For example::
        
            tar xf python-gphoto2-gphoto2-0.3.2.tar.gz
            cd python-gphoto2-gphoto2-0.3.2
        
        As before, Python's ``distutils`` are used to build and install python-gphoto2::
        
            python setup.py build
            sudo python setup.py install
        
        Testing
        ^^^^^^^
        
        .. note:: If you installed with pip the example files should be in ``/usr/share/python-gphoto2/examples`` or ``/usr/local/share/python-gphoto2/examples`` or somewhere similar (except for versions before 0.3.2, which didn't install the examples at all).
        
        Connect a digital camera to your computer, switch it on, and try one of the example programs::
        
            python examples/camera-summary.py
        
        If this works then you're ready to start using python-gphoto2.
        
        Using python-gphoto2
        --------------------
        
        The Python interface to libgphoto2 should allow you to do anything you could do in a C program.
        However, the project is quite young and there are still bits missing and functions that cannot be called from Python.
        Let me know if you run into any problems.
        
        The following paragraphs show how the Python interfaces differ from C.
        See the example programs for typical usage of the Python gphoto2 API.
        
        "C" interface
        ^^^^^^^^^^^^^
        
        Using SWIG to generate the Python interfaces automatically means that every function in libgphoto2 *should* be available to Python.
        The ``pydoc`` command can be used to show basic information about a function::
        
           jim@firefly ~/python-gphoto2 $ pydoc gphoto2.gp_camera_folder_list_files
           Help on built-in function gp_camera_folder_list_files in gphoto2:
        
           gphoto2.gp_camera_folder_list_files = gp_camera_folder_list_files(...)
               gp_camera_folder_list_files(camera, folder, context) -> int
        
               Parameters:
                   camera: Camera *
                   folder: char const *
                   context: GPContext *
           jim@firefly ~/python-gphoto2 $
        
        In general it is easier to use the C `API documentation <http://www.gphoto.org/doc/api/>`_, but make sure you find the documentation for the version of libgphoto2 installed on your computer.
        
        Note that there is one major difference between the Python and C APIs.
        C functions that use a pointer parameter to return a value (and often do some memory allocation) such as `gp_camera_new() <http://www.gphoto.org/doc/api/gphoto2-camera_8h.html>`_ have Python equivalents that create the required pointer and return it in a list with the gphoto2 error code.
        
        For example, the C code:
        
        .. code:: c
        
            #include "gphoto2.h"
            int error;
            Camera *camera;
            error = gp_camera_new(&camera);
            ...
            error = gp_camera_unref(camera);
        
        has this Python equivalent:
        
        .. code:: python
        
            import gphoto2 as gp
            error, camera = gp.gp_camera_new()
            ...
        
        Note that the gp_camera_unref() call is not needed (since version 0.5.0).
        It is called automatically when the python camera object is deleted.
        
        This conversion of "output" parameters is why the ``CameraList *list`` parameter is not included in the ``pydoc`` example above but is shown in the C documentation.
        In Python a new ``CameraList`` object is created and appended to the return value list.
        Unfortunately I've not found a way to persuade SWIG to include this extra return value in the documentation.
        
        Here is a complete example program (without any error checking):
        
        .. code:: python
        
            import gphoto2 as gp
            context = gp.gp_context_new()
            error, camera = gp.gp_camera_new()
            error = gp.gp_camera_init(camera, context)
            error, text = gp.gp_camera_get_summary(camera, context)
            print('Summary')
            print('=======')
            print(text.text)
            error = gp.gp_camera_exit(camera, context)
        
        "Object oriented" interface
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^
        
        SWIG has the ability to attach member functions to C structs such as the GPhoto2 ``Camera`` object.
        The Python interface includes many such member functions, allowing GPhoto2 to be used in a more "Pythonic" style.
        These member functions also include error checking.
        If an error occurs they raise a Python ``GPhoto2Error`` exception.
        
        The example program can be re-written as follows:
        
        .. code:: python
        
            import gphoto2 as gp
            context = gp.Context()
            camera = gp.Camera()
            camera.init(context)
            text = camera.get_summary(context)
            print('Summary')
            print('=======')
            print(str(text))
            camera.exit(context)
        
        The member functions are more "hand crafted" than the rest of the Python bindings, which are mostly automatically generated from the library header files.
        This means that there may be some functions in the "C" interface that do not have corresponding member methods.
        
        Error checking
        ^^^^^^^^^^^^^^
        
        Most of the libgphoto2 "C" functions return an integer to indicate success or failure.
        The Python interface includes a ``check_result()`` function to check these values and raise a ``GPhoto2Error`` exception if an error occurs.
        
        This function also unwraps lists such as that returned by ``gp_camera_new()`` in the example.
        Using this function the earlier example becomes:
        
        .. code:: python
        
            import gphoto2 as gp
            context = gp.gp_context_new()
            camera = gp.check_result(gp.gp_camera_new())
            gp.check_result(gp.gp_camera_init(camera, context))
            text = gp.check_result(gp.gp_camera_get_summary(camera, context))
            print('Summary')
            print('=======')
            print(text.text)
            gp.check_result(gp.gp_camera_exit(camera, context))
        
        There may be some circumstances where you don't want an exception to be raised when some errors occur.
        You can "fine tune" the behaviour of the ``check_result()`` function by adjusting the ``error_severity`` variable:
        
        .. code:: python
        
            import gphoto2 as gp
            gp.error_severity[gp.GP_ERROR] = logging.WARNING
            ...
        
        In this case a warning message will be logged (using Python's standard logging module) but no exception will be raised when a ``GP_ERROR`` error occurs.
        However, this is a "blanket" approach that treats all ``GP_ERROR`` errors the same.
        It is better to test for particular error conditions after particular operations, as described below.
        
        The ``GPhoto2Error`` exception object has two attributes that may be useful in an exception handler.
        ``GPhoto2Error.code`` stores the integer error generated by the library function and ``GPhoto2Error.string`` stores the corresponding error message.
        
        For example, to wait for a user to connect a camera you could do something like this:
        
        .. code:: python
        
            import gphoto2 as gp
            ...
            print('Please connect and switch on your camera')
            while True:
                try:
                    camera.init(context)
                except gp.GPhoto2Error as ex:
                    if ex.code == gp.GP_ERROR_MODEL_NOT_FOUND:
                        # no camera, try again in 2 seconds
                        time.sleep(2)
                        continue
                    # some other error we can't handle here
                    raise
                # operation completed successfully so exit loop
                break
            # continue with rest of program
            ...
        
        When just calling a single function like this, it's probably easier to test the error value directly instead of using Python exceptions:
        
        .. code:: python
        
            import gphoto2 as gp
            ...
            print('Please connect and switch on your camera')
            while True:
                error = gp.gp_camera_init(camera, context)
                if error >= gp.GP_OK:
                    # operation completed successfully so exit loop
                    break
                if error != gp.GP_ERROR_MODEL_NOT_FOUND:
                    # some other error we can't handle here
                    raise gp.GPhoto2Error(error)
                # no camera, try again in 2 seconds
                time.sleep(2)
            # continue with rest of program
            ...
        
        Licence
        -------
        
        python-gphoto2 - Python interface to libgphoto2
        http://github.com/jim-easterbrook/python-gphoto2
        Copyright (C) 2014  Jim Easterbrook  jim@jim-easterbrook.me.uk
        
        This program is free software: you can redistribute it and/or modify
        it under the terms of the GNU General Public License as published by
        the Free Software Foundation, either version 3 of the License, or
        (at your option) any later version.
        
        This program is distributed in the hope that it will be useful,
        but WITHOUT ANY WARRANTY; without even the implied warranty of
        MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
        GNU General Public License for more details.
        
        You should have received a copy of the GNU General Public License
        along with this program.  If not, see http://www.gnu.org/licenses/.
        
Platform: POSIX
Platform: MacOS
Classifier: Development Status :: 4 - Beta
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: GNU General Public License v3 or later (GPLv3+)
Classifier: Operating System :: MacOS
Classifier: Operating System :: MacOS :: MacOS X
Classifier: Operating System :: POSIX
Classifier: Operating System :: POSIX :: BSD :: FreeBSD
Classifier: Operating System :: POSIX :: BSD :: NetBSD
Classifier: Operating System :: POSIX :: Linux
Classifier: Programming Language :: Python :: 2
Classifier: Programming Language :: Python :: 2.6
Classifier: Programming Language :: Python :: 2.7
Classifier: Programming Language :: Python :: 3
Classifier: Topic :: Multimedia
Classifier: Topic :: Multimedia :: Graphics
Classifier: Topic :: Multimedia :: Graphics :: Capture
