Python matplotlib.testing() Examples

def switch_backend(backend):

    def switch_backend_decorator(func):

        @functools.wraps(func)
        def backend_switcher(*args, **kwargs):
            try:
                prev_backend = mpl.get_backend()
                matplotlib.testing.setup()
                plt.switch_backend(backend)
                return func(*args, **kwargs)
            finally:
                plt.switch_backend(prev_backend)

        return backend_switcher

    return switch_backend_decorator 

def switch_backend(backend):

    def switch_backend_decorator(func):

        @functools.wraps(func)
        def backend_switcher(*args, **kwargs):
            try:
                prev_backend = mpl.get_backend()
                matplotlib.testing.setup()
                plt.switch_backend(backend)
                return func(*args, **kwargs)
            finally:
                plt.switch_backend(prev_backend)

        return backend_switcher

    return switch_backend_decorator 

def switch_backend(backend):

    def switch_backend_decorator(func):

        @functools.wraps(func)
        def backend_switcher(*args, **kwargs):
            try:
                prev_backend = mpl.get_backend()
                matplotlib.testing.setup()
                plt.switch_backend(backend)
                return func(*args, **kwargs)
            finally:
                plt.switch_backend(prev_backend)

        return backend_switcher

    return switch_backend_decorator 

def switch_backend(backend):

    def switch_backend_decorator(func):

        @functools.wraps(func)
        def backend_switcher(*args, **kwargs):
            try:
                prev_backend = mpl.get_backend()
                matplotlib.testing.setup()
                plt.switch_backend(backend)
                return func(*args, **kwargs)
            finally:
                plt.switch_backend(prev_backend)

        return backend_switcher

    return switch_backend_decorator 

def switch_backend(backend):
    # Local import to avoid a hard nose dependency and only incur the
    # import time overhead at actual test-time.
    def switch_backend_decorator(func):
        @functools.wraps(func)
        def backend_switcher(*args, **kwargs):
            try:
                prev_backend = mpl.get_backend()
                matplotlib.testing.setup()
                plt.switch_backend(backend)
                result = func(*args, **kwargs)
            finally:
                plt.switch_backend(prev_backend)
            return result

        return _copy_metadata(func, backend_switcher)
    return switch_backend_decorator 

def setup(self):
        func = self.func
        plt.close('all')
        self.setup_class()
        try:
            matplotlib.style.use(self.style)
            matplotlib.testing.set_font_settings_for_testing()
            func()
            assert len(plt.get_fignums()) == len(self.baseline_images), (
                "Test generated {} images but there are {} baseline images"
                .format(len(plt.get_fignums()), len(self.baseline_images)))
        except:
            # Restore original settings before raising errors.
            self.teardown_class()
            raise 

def _image_directories(func):
    """
    Compute the baseline and result image directories for testing *func*.

    For test module ``foo.bar.test_baz``, the baseline directory is at
    ``foo/bar/baseline_images/test_baz`` and the result directory at
    ``$(pwd)/result_images/test_baz``.  The result directory is created if it
    doesn't exist.
    """
    module_path = Path(sys.modules[func.__module__].__file__)
    baseline_dir = module_path.parent / "baseline_images" / module_path.stem
    result_dir = Path().resolve() / "result_images" / module_path.stem
    result_dir.mkdir(parents=True, exist_ok=True)
    return str(baseline_dir), str(result_dir) 

def setup(self):
        func = self.func
        plt.close('all')
        self.setup_class()
        try:
            matplotlib.style.use(self.style)
            matplotlib.testing.set_font_settings_for_testing()
            func()
            assert len(plt.get_fignums()) == len(self.baseline_images), (
                "Test generated {} images but there are {} baseline images"
                .format(len(plt.get_fignums()), len(self.baseline_images)))
        except:
            # Restore original settings before raising errors.
            self.teardown_class()
            raise 

def _image_directories(func):
    """
    Compute the baseline and result image directories for testing *func*.

    For test module ``foo.bar.test_baz``, the baseline directory is at
    ``foo/bar/baseline_images/test_baz`` and the result directory at
    ``$(pwd)/result_images/test_baz``.  The result directory is created if it
    doesn't exist.
    """
    module_path = Path(sys.modules[func.__module__].__file__)
    baseline_dir = module_path.parent / "baseline_images" / module_path.stem
    result_dir = Path().resolve() / "result_images" / module_path.stem
    result_dir.mkdir(parents=True, exist_ok=True)
    return str(baseline_dir), str(result_dir) 

def knownfailureif(fail_condition, msg=None, known_exception_class=None ):
    """

    Assume a will fail if *fail_condition* is True. *fail_condition*
    may also be False or the string 'indeterminate'.

    *msg* is the error message displayed for the test.

    If *known_exception_class* is not None, the failure is only known
    if the exception is an instance of this class. (Default = None)

    """
    # based on numpy.testing.dec.knownfailureif
    if msg is None:
        msg = 'Test known to fail'
    def known_fail_decorator(f):
        # Local import to avoid a hard nose dependency and only incur the
        # import time overhead at actual test-time.
        import nose
        def failer(*args, **kwargs):
            try:
                # Always run the test (to generate images).
                result = f(*args, **kwargs)
            except Exception as err:
                if fail_condition:
                    if known_exception_class is not None:
                        if not isinstance(err,known_exception_class):
                            # This is not the expected exception
                            raise
                    # (Keep the next ultra-long comment so in shows in console.)
                    raise KnownFailure(msg) # An error here when running nose means that you don't have the matplotlib.testing.noseclasses:KnownFailure plugin in use.
                else:
                    raise
            if fail_condition and fail_condition != 'indeterminate':
                raise KnownFailureDidNotFailTest(msg)
            return result
        return nose.tools.make_decorator(f)(failer)
    return known_fail_decorator 

def _do_cleanup(original_units_registry):
    plt.close('all')
    gc.collect()

    import matplotlib.testing
    matplotlib.testing.setup()

    matplotlib.units.registry.clear()
    matplotlib.units.registry.update(original_units_registry)
    warnings.resetwarnings()  # reset any warning filters set in tests 

def _image_directories(func):
    """
    Compute the baseline and result image directories for testing *func*.
    Create the result directory if it doesn't exist.
    """
    module_name = func.__module__
#     mods = module_name.split('.')
#     mods.pop(0) # <- will be the name of the package being tested (in
                # most cases "matplotlib")
#     assert mods.pop(0) == 'tests'
#     subdir = os.path.join(*mods)
    subdir = module_name

    import imp
    def find_dotted_module(module_name, path=None):
        """A version of imp which can handle dots in the module name"""
        res = None
        for sub_mod in module_name.split('.'):
            try:
                res = file, path, _ = imp.find_module(sub_mod, path)
                path = [path]
                if file is not None:
                    file.close()
            except ImportError:
                # assume namespace package
                path = sys.modules[sub_mod].__path__
                res = None, path, None
        return res

    mod_file = find_dotted_module(func.__module__)[1]
    basedir = os.path.dirname(mod_file)

    baseline_dir = os.path.join(basedir, 'baseline_images', subdir)
    result_dir = os.path.abspath(os.path.join('result_images', subdir))

    if not os.path.exists(result_dir):
        cbook.mkdirs(result_dir)

    return baseline_dir, result_dir 

def setup(self):
        func = self.func
        plt.close('all')
        self.setup_class()
        try:
            matplotlib.style.use(self.style)
            matplotlib.testing.set_font_settings_for_testing()
            func()
            assert len(plt.get_fignums()) == len(self.baseline_images), (
                "Test generated {} images but there are {} baseline images"
                .format(len(plt.get_fignums()), len(self.baseline_images)))
        except:
            # Restore original settings before raising errors.
            self.teardown_class()
            raise 

def _image_directories(func):
    """
    Compute the baseline and result image directories for testing *func*.

    For test module ``foo.bar.test_baz``, the baseline directory is at
    ``foo/bar/baseline_images/test_baz`` and the result directory at
    ``$(pwd)/result_images/test_baz``.  The result directory is created if it
    doesn't exist.
    """
    module_path = Path(sys.modules[func.__module__].__file__)
    baseline_dir = module_path.parent / "baseline_images" / module_path.stem
    result_dir = Path().resolve() / "result_images" / module_path.stem
    result_dir.mkdir(parents=True, exist_ok=True)
    return str(baseline_dir), str(result_dir) 

def setup(self):
        func = self.func
        plt.close('all')
        self.setup_class()
        try:
            matplotlib.style.use(self.style)
            matplotlib.testing.set_font_settings_for_testing()
            func()
            assert len(plt.get_fignums()) == len(self.baseline_images), (
                "Test generated {} images but there are {} baseline images"
                .format(len(plt.get_fignums()), len(self.baseline_images)))
        except:
            # Restore original settings before raising errors.
            self.teardown_class()
            raise 

def _image_directories(func):
    """
    Compute the baseline and result image directories for testing *func*.

    For test module ``foo.bar.test_baz``, the baseline directory is at
    ``foo/bar/baseline_images/test_baz`` and the result directory at
    ``$(pwd)/result_images/test_baz``.  The result directory is created if it
    doesn't exist.
    """
    module_path = Path(sys.modules[func.__module__].__file__)
    baseline_dir = module_path.parent / "baseline_images" / module_path.stem
    result_dir = Path().resolve() / "result_images" / module_path.stem
    result_dir.mkdir(parents=True, exist_ok=True)
    return str(baseline_dir), str(result_dir) 

def setup_class(cls):
        cls.original_units_registry = matplotlib.units.registry.copy()
        cls.original_settings = mpl.rcParams.copy()
        matplotlib.testing.setup() 

def setup(self):
        func = self.func
        plt.close('all')
        self.setup_class()
        try:
            matplotlib.style.use(self.style)
            matplotlib.testing.set_font_settings_for_testing()
            func()
            assert len(plt.get_fignums()) == len(self.baseline_images), (
                "Test generated {} images but there are {} baseline images"
                .format(len(plt.get_fignums()), len(self.baseline_images)))
        except:
            # Restore original settings before raising errors.
            self.teardown_class()
            raise 

def _pytest_image_comparison(baseline_images, extensions, tol,
                             freetype_version, remove_text, savefig_kwargs,
                             style):
    """
    Decorate function with image comparison for pytest.

    This function creates a decorator that wraps a figure-generating function
    with image comparison code. Pytest can become confused if we change the
    signature of the function, so we indirectly pass anything we need via the
    `mpl_image_comparison_parameters` fixture and extra markers.
    """
    import pytest

    extensions = map(_mark_xfail_if_format_is_uncomparable, extensions)

    def decorator(func):
        @functools.wraps(func)
        # Parameter indirection; see docstring above and comment below.
        @pytest.mark.usefixtures('mpl_image_comparison_parameters')
        @pytest.mark.parametrize('extension', extensions)
        @pytest.mark.baseline_images(baseline_images)
        # END Parameter indirection.
        @pytest.mark.style(style)
        @_checked_on_freetype_version(freetype_version)
        @functools.wraps(func)
        def wrapper(*args, **kwargs):
            __tracebackhide__ = True
            img = _ImageComparisonBase(tol=tol, remove_text=remove_text,
                                       savefig_kwargs=savefig_kwargs)
            img.delayed_init(func)
            matplotlib.testing.set_font_settings_for_testing()
            func(*args, **kwargs)

            # Parameter indirection:
            # This is hacked on via the mpl_image_comparison_parameters fixture
            # so that we don't need to modify the function's real signature for
            # any parametrization. Modifying the signature is very very tricky
            # and likely to confuse pytest.
            baseline_images, extension = func.parameters

            assert len(plt.get_fignums()) == len(baseline_images), (
                "Test generated {} images but there are {} baseline images"
                .format(len(plt.get_fignums()), len(baseline_images)))
            for idx, baseline in enumerate(baseline_images):
                img.compare(idx, baseline, extension)

        return wrapper

    return decorator 

def _pytest_image_comparison(baseline_images, extensions, tol,
                             freetype_version, remove_text, savefig_kwargs,
                             style):
    """
    Decorate function with image comparison for pytest.

    This function creates a decorator that wraps a figure-generating function
    with image comparison code. Pytest can become confused if we change the
    signature of the function, so we indirectly pass anything we need via the
    `mpl_image_comparison_parameters` fixture and extra markers.
    """
    import pytest

    extensions = map(_mark_xfail_if_format_is_uncomparable, extensions)

    def decorator(func):
        @functools.wraps(func)
        # Parameter indirection; see docstring above and comment below.
        @pytest.mark.usefixtures('mpl_image_comparison_parameters')
        @pytest.mark.parametrize('extension', extensions)
        @pytest.mark.baseline_images(baseline_images)
        # END Parameter indirection.
        @pytest.mark.style(style)
        @_checked_on_freetype_version(freetype_version)
        @functools.wraps(func)
        def wrapper(*args, **kwargs):
            __tracebackhide__ = True
            img = _ImageComparisonBase(tol=tol, remove_text=remove_text,
                                       savefig_kwargs=savefig_kwargs)
            img.delayed_init(func)
            matplotlib.testing.set_font_settings_for_testing()
            func(*args, **kwargs)

            # Parameter indirection:
            # This is hacked on via the mpl_image_comparison_parameters fixture
            # so that we don't need to modify the function's real signature for
            # any parametrization. Modifying the signature is very very tricky
            # and likely to confuse pytest.
            baseline_images, extension = func.parameters

            assert len(plt.get_fignums()) == len(baseline_images), (
                "Test generated {} images but there are {} baseline images"
                .format(len(plt.get_fignums()), len(baseline_images)))
            for idx, baseline in enumerate(baseline_images):
                img.compare(idx, baseline, extension)

        return wrapper

    return decorator 

def _pytest_image_comparison(baseline_images, extensions, tol,
                             freetype_version, remove_text, savefig_kwargs,
                             style):
    """
    Decorate function with image comparison for pytest.

    This function creates a decorator that wraps a figure-generating function
    with image comparison code. Pytest can become confused if we change the
    signature of the function, so we indirectly pass anything we need via the
    `mpl_image_comparison_parameters` fixture and extra markers.
    """
    import pytest

    extensions = map(_mark_xfail_if_format_is_uncomparable, extensions)

    def decorator(func):
        @functools.wraps(func)
        # Parameter indirection; see docstring above and comment below.
        @pytest.mark.usefixtures('mpl_image_comparison_parameters')
        @pytest.mark.parametrize('extension', extensions)
        @pytest.mark.baseline_images(baseline_images)
        # END Parameter indirection.
        @pytest.mark.style(style)
        @_checked_on_freetype_version(freetype_version)
        @functools.wraps(func)
        def wrapper(*args, **kwargs):
            __tracebackhide__ = True
            img = _ImageComparisonBase(tol=tol, remove_text=remove_text,
                                       savefig_kwargs=savefig_kwargs)
            img.delayed_init(func)
            matplotlib.testing.set_font_settings_for_testing()
            func(*args, **kwargs)

            # Parameter indirection:
            # This is hacked on via the mpl_image_comparison_parameters fixture
            # so that we don't need to modify the function's real signature for
            # any parametrization. Modifying the signature is very very tricky
            # and likely to confuse pytest.
            baseline_images, extension = func.parameters

            assert len(plt.get_fignums()) == len(baseline_images), (
                "Test generated {} images but there are {} baseline images"
                .format(len(plt.get_fignums()), len(baseline_images)))
            for idx, baseline in enumerate(baseline_images):
                img.compare(idx, baseline, extension)

        return wrapper

    return decorator 

def _pytest_image_comparison(baseline_images, extensions, tol,
                             freetype_version, remove_text, savefig_kwargs,
                             style):
    """
    Decorate function with image comparison for pytest.

    This function creates a decorator that wraps a figure-generating function
    with image comparison code. Pytest can become confused if we change the
    signature of the function, so we indirectly pass anything we need via the
    `mpl_image_comparison_parameters` fixture and extra markers.
    """
    import pytest

    extensions = map(_mark_skip_if_format_is_uncomparable, extensions)

    def decorator(func):
        @functools.wraps(func)
        # Parameter indirection; see docstring above and comment below.
        @pytest.mark.usefixtures('mpl_image_comparison_parameters')
        @pytest.mark.parametrize('extension', extensions)
        @pytest.mark.baseline_images(baseline_images)
        # END Parameter indirection.
        @pytest.mark.style(style)
        @_checked_on_freetype_version(freetype_version)
        @functools.wraps(func)
        def wrapper(*args, **kwargs):
            __tracebackhide__ = True
            img = _ImageComparisonBase(tol=tol, remove_text=remove_text,
                                       savefig_kwargs=savefig_kwargs)
            img.delayed_init(func)
            matplotlib.testing.set_font_settings_for_testing()
            func(*args, **kwargs)

            # Parameter indirection:
            # This is hacked on via the mpl_image_comparison_parameters fixture
            # so that we don't need to modify the function's real signature for
            # any parametrization. Modifying the signature is very very tricky
            # and likely to confuse pytest.
            baseline_images, extension = func.parameters

            assert len(plt.get_fignums()) == len(baseline_images), (
                "Test generated {} images but there are {} baseline images"
                .format(len(plt.get_fignums()), len(baseline_images)))
            for idx, baseline in enumerate(baseline_images):
                img.compare(idx, baseline, extension)

        return wrapper

    return decorator 

def _pytest_image_comparison(baseline_images, extensions, tol,
                             freetype_version, remove_text, savefig_kwargs,
                             style):
    """
    Decorate function with image comparison for pytest.

    This function creates a decorator that wraps a figure-generating function
    with image comparison code. Pytest can become confused if we change the
    signature of the function, so we indirectly pass anything we need via the
    `mpl_image_comparison_parameters` fixture and extra markers.
    """
    import pytest

    extensions = map(_mark_xfail_if_format_is_uncomparable, extensions)

    def decorator(func):
        # Parameter indirection; see docstring above and comment below.
        @pytest.mark.usefixtures('mpl_image_comparison_parameters')
        @pytest.mark.parametrize('extension', extensions)
        @pytest.mark.baseline_images(baseline_images)
        # END Parameter indirection.
        @pytest.mark.style(style)
        @_checked_on_freetype_version(freetype_version)
        @functools.wraps(func)
        def wrapper(*args, **kwargs):
            __tracebackhide__ = True
            img = _ImageComparisonBase(tol=tol, remove_text=remove_text,
                                       savefig_kwargs=savefig_kwargs)
            img.delayed_init(func)
            matplotlib.testing.set_font_settings_for_testing()
            func(*args, **kwargs)

            # Parameter indirection:
            # This is hacked on via the mpl_image_comparison_parameters fixture
            # so that we don't need to modify the function's real signature for
            # any parametrization. Modifying the signature is very very tricky
            # and likely to confuse pytest.
            baseline_images, extension = func.parameters

            assert len(plt.get_fignums()) == len(baseline_images), (
                "Test generated {} images but there are {} baseline images"
                .format(len(plt.get_fignums()), len(baseline_images)))
            for idx, baseline in enumerate(baseline_images):
                img.compare(idx, baseline, extension)

        wrapper.__wrapped__ = func  # For Python 2.7.
        return _copy_metadata(func, wrapper)

    return decorator 

def _image_directories(func):
    """
    Compute the baseline and result image directories for testing *func*.
    Create the result directory if it doesn't exist.
    """
    module_name = func.__module__
    if module_name == '__main__':
        # FIXME: this won't work for nested packages in matplotlib.tests
        warnings.warn(
            'Test module run as script. Guessing baseline image locations.')
        script_name = sys.argv[0]
        basedir = os.path.abspath(os.path.dirname(script_name))
        subdir = os.path.splitext(os.path.split(script_name)[1])[0]
    else:
        mods = module_name.split('.')
        if len(mods) >= 3:
            mods.pop(0)
            # mods[0] will be the name of the package being tested (in
            # most cases "matplotlib") However if this is a
            # namespace package pip installed and run via the nose
            # multiprocess plugin or as a specific test this may be
            # missing. See https://github.com/matplotlib/matplotlib/issues/3314
        if mods.pop(0) != 'tests':
            warnings.warn(
                "Module {!r} does not live in a parent module named 'tests'. "
                "This is probably ok, but we may not be able to guess the "
                "correct subdirectory containing the baseline images. If "
                "things go wrong please make sure that there is a parent "
                "directory named 'tests' and that it contains a __init__.py "
                "file (can be empty).".format(module_name))
        subdir = os.path.join(*mods)

        import imp
        def find_dotted_module(module_name, path=None):
            """A version of imp which can handle dots in the module name.
               As for imp.find_module(), the return value is a 3-element
               tuple (file, pathname, description)."""
            res = None
            for sub_mod in module_name.split('.'):
                try:
                    res = file, path, _ = imp.find_module(sub_mod, path)
                    path = [path]
                    if file is not None:
                        file.close()
                except ImportError:
                    # assume namespace package
                    path = list(sys.modules[sub_mod].__path__)
                    res = None, path, None
            return res

        mod_file = find_dotted_module(func.__module__)[1]
        basedir = os.path.dirname(mod_file)

    baseline_dir = os.path.join(basedir, 'baseline_images', subdir)
    result_dir = os.path.abspath(os.path.join('result_images', subdir))

    if not os.path.exists(result_dir):
        cbook.mkdirs(result_dir)

    return baseline_dir, result_dir