Source code for picamera.exc

# vim: set et sw=4 sts=4 fileencoding=utf-8:
#
# Python camera library for the Rasperry-Pi camera module
# Copyright (c) 2013-2015 Dave Jones <dave@waveform.org.uk>
#
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"""
This module defines the exceptions used by picamera. All exception classes
utilize multiple inheritance in order to make testing for exception types more
intuitive. For example, :exc:`PiCameraValueError` derives from both
:exc:`PiCameraError` and :exc:`ValueError`. Hence it will be caught by blocks
intended to catch any error specific to the picamera library::

    try:
        camera.brightness = int(some_user_value)
    except PiCameraError:
        print('Something went wrong with the camera')

Or by blocks intended to catch value errors::

    try:
        camera.contrast = int(some_user_value)
    except ValueError:
        print('Invalid value')

.. note::

    All classes in this module are available from the :mod:`picamera` namespace
    without having to import :mod:`picamera.streams` directly.

The following classes are defined in the module:


.. autoexception:: PiCameraWarning

.. autoexception:: PiCameraDeprecated

.. autoexception:: PiCameraFallback

.. autoexception:: PiCameraError

.. autoexception:: PiCameraValueError

.. autoexception:: PiCameraRuntimeError

.. autoexception:: PiCameraClosed

.. autoexception:: PiCameraNotRecording

.. autoexception:: PiCameraAlreadyRecording

.. autoexception:: PiCameraMMALError

.. autofunction:: mmal_check

"""

from __future__ import (
    unicode_literals,
    print_function,
    division,
    absolute_import,
    )

# Make Py2's str equivalent to Py3's
str = type('')


import picamera.mmal as mmal


[docs]class PiCameraWarning(Warning): """ Base class for PiCamera warnings. """
[docs]class PiCameraDeprecated(PiCameraWarning, DeprecationWarning): """ Raised when deprecated functionality in picamera is used. """
[docs]class PiCameraFallback(PiCameraWarning, RuntimeWarning): """ Raised when picamera has to fallback on old functionality. """
[docs]class PiCameraError(Exception): """ Base class for PiCamera errors. """
[docs]class PiCameraRuntimeError(PiCameraError, RuntimeError): """ Raised when an invalid sequence of operations is attempted with a :class:`~picamera.camera.PiCamera` object. """
[docs]class PiCameraClosed(PiCameraRuntimeError): """ Raised when a method is called on a camera which has already been closed. """
[docs]class PiCameraNotRecording(PiCameraRuntimeError): """ Raised when :meth:`~picamera.camera.PiCamera.stop_recording` or :meth:`~picamera.camera.PiCamera.split_recording` are called against a port which has no recording active. """
[docs]class PiCameraAlreadyRecording(PiCameraRuntimeError): """ Raised when :meth:`~picamera.camera.PiCamera.start_recording` or :meth:`~picamera.camera.PiCamera.record_sequence` are called against a port which already has an active recording. """
[docs]class PiCameraValueError(PiCameraError, ValueError): """ Raised when an invalid value is fed to a :class:`~picamera.camera.PiCamera` object. """
[docs]class PiCameraMMALError(PiCameraError): """ Raised when an MMAL operation fails for whatever reason. """ def __init__(self, status, prefix=""): self.status = status PiCameraError.__init__(self, "%s%s%s" % (prefix, ": " if prefix else "", { mmal.MMAL_ENOMEM: "Out of memory", mmal.MMAL_ENOSPC: "Out of resources (other than memory)", mmal.MMAL_EINVAL: "Argument is invalid", mmal.MMAL_ENOSYS: "Function not implemented", mmal.MMAL_ENOENT: "No such file or directory", mmal.MMAL_ENXIO: "No such device or address", mmal.MMAL_EIO: "I/O error", mmal.MMAL_ESPIPE: "Illegal seek", mmal.MMAL_ECORRUPT: "Data is corrupt #FIXME not POSIX", mmal.MMAL_ENOTREADY: "Component is not ready #FIXME not POSIX", mmal.MMAL_ECONFIG: "Component is not configured #FIXME not POSIX", mmal.MMAL_EISCONN: "Port is already connected", mmal.MMAL_ENOTCONN: "Port is disconnected", mmal.MMAL_EAGAIN: "Resource temporarily unavailable; try again later", mmal.MMAL_EFAULT: "Bad address", }.get(status, "Unknown status error")))
[docs]def mmal_check(status, prefix=""): """ Checks the return status of an mmal call and raises an exception on failure. The *status* parameter is the result of an MMAL call. If *status* is anything other than MMAL_SUCCESS, a :exc:`PiCameraMMALError` exception is raised. The optional *prefix* parameter specifies a prefix message to place at the start of the exception's message to provide some context. """ if status != mmal.MMAL_SUCCESS: raise PiCameraMMALError(status, prefix)