Improve the error message when an import is missing

menpo · Dec 3, 2017 · f6c9a23 · f6c9a23
1 parent a86a4a7
commit f6c9a23
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Showing 12 changed files with 67 additions and 52 deletions.
diff --git a/menpo/base.py b/menpo/base.py
@@ -4,6 +4,7 @@
 import os.path
 from pprint import pformat
 import warnings
+import textwrap
 
 
 class Copyable(object):
@@ -330,18 +331,28 @@ class MenpoDeprecationWarning(Warning):
     pass
 
 
-class MenpoMissingDependencyError(Exception):
+class MenpoMissingDependencyError(ImportError):
     r"""
     An exception that a dependency required for the requested functionality
     was not detected.
     """
     def __init__(self, package_name):
         super(MenpoMissingDependencyError, self).__init__()
-        self.message = "You need to install the '{pname}' package in order " \
-                       "to use this functionality. We recommend that you " \
-                       "use conda to achieve this - try the command " \
-                       "'conda install -c menpo {pname}' " \
-                       "in your terminal.".format(pname=package_name)
+        self.message = textwrap.dedent("""
+            You need to install the '{pname}' package in order to use this
+            functionality. We recommend that you use conda to achieve this -
+            try the command
+
+                conda install {pname}
+
+            in your terminal. Note that this package may be provided by another
+            channel such as the "menpo" channel or the "conda-forge" channel.
+            Failing that, try installing use pip:
+
+                pip install {pname}
+        """.format(pname=package_name))
+
+        self.missing_name = package_name
 
     def __str__(self):
         return self.message
@@ -700,9 +711,9 @@ def view_widget(self):
         """
         try:
             from menpowidgets import view_widget
-        except ImportError:
+        except ImportError as e:
             from menpo.visualize.base import MenpowidgetsMissingError
-            raise MenpowidgetsMissingError()
+            raise MenpowidgetsMissingError(e.name)
         else:
             return view_widget(self)
 

diff --git a/menpo/feature/optional/vlfeat.py b/menpo/feature/optional/vlfeat.py
@@ -6,8 +6,8 @@
 
 try:
     from cyvlfeat.sift.dsift import dsift as cyvlfeat_dsift
-except ImportError:
-    raise MenpoMissingDependencyError('cyvlfeat')
+except ImportError as e:
+    raise MenpoMissingDependencyError(e.name)
 
 
 @winitfeature

diff --git a/menpo/image/base.py b/menpo/image/base.py
@@ -848,9 +848,9 @@ def view_widget(self, figure_size=(7, 7)):
         try:
             from menpowidgets import view_widget
             view_widget(self, figure_size=figure_size)
-        except ImportError:
+        except ImportError as e:
             from menpo.visualize.base import MenpowidgetsMissingError
-            raise MenpowidgetsMissingError()
+            raise MenpowidgetsMissingError(e.name)
 
     def _view_landmarks_2d(self, channels=None, group=None,
                            with_labels=None, without_labels=None,

diff --git a/menpo/landmark/base.py b/menpo/landmark/base.py
@@ -315,9 +315,9 @@ def _view_widget_2d(self, figure_size=(7, 7)):
         try:
             from menpowidgets import view_widget
             view_widget(self, figure_size=figure_size)
-        except ImportError:
+        except ImportError as e:
             from menpo.visualize.base import MenpowidgetsMissingError
-            raise MenpowidgetsMissingError()
+            raise MenpowidgetsMissingError(e.name)
 
     def _view_widget_3d(self):
         r"""
@@ -326,9 +326,9 @@ def _view_widget_3d(self):
         try:
             from menpowidgets import view_widget
             view_widget(self)
-        except ImportError:
+        except ImportError as e:
             from menpo.visualize.base import MenpowidgetsMissingError
-            raise MenpowidgetsMissingError()
+            raise MenpowidgetsMissingError(e.name)
 
     def __str__(self):
         out_string = '{}: n_groups: {}'.format(type(self).__name__,

diff --git a/menpo/model/pca.py b/menpo/model/pca.py
@@ -832,9 +832,9 @@ def plot_eigenvalues_widget(self, figure_size=(10, 6), style='coloured'):
         """
         try:
             from menpowidgets import plot_graph
-        except:
+        except ImportError as e:
             from menpo.visualize.base import MenpowidgetsMissingError
-            raise MenpowidgetsMissingError()
+            raise MenpowidgetsMissingError(e.name)
         plot_graph(x_axis=range(self.n_active_components),
                    y_axis=[self.eigenvalues], legend_entries=['Eigenvalues'],
                    figure_size=figure_size, style=style)
@@ -981,9 +981,9 @@ def plot_eigenvalues_ratio_widget(self, figure_size=(10, 6),
         """
         try:
             from menpowidgets import plot_graph
-        except:
+        except ImportError as e:
             from menpo.visualize.base import MenpowidgetsMissingError
-            raise MenpowidgetsMissingError()
+            raise MenpowidgetsMissingError(e.name)
         plot_graph(x_axis=range(self.n_active_components),
                    y_axis=[self.eigenvalues_ratio()],
                    legend_entries=['Eigenvalues ratio'],
@@ -1137,9 +1137,9 @@ def plot_eigenvalues_cumulative_ratio_widget(self, figure_size=(10, 6),
         """
         try:
             from menpowidgets import plot_graph
-        except:
+        except ImportError as e:
             from menpo.visualize.base import MenpowidgetsMissingError
-            raise MenpowidgetsMissingError()
+            raise MenpowidgetsMissingError(e.name)
         plot_graph(x_axis=range(self.n_active_components),
                    y_axis=[self.eigenvalues_cumulative_ratio()],
                    legend_entries=['Eigenvalues cumulative ratio'],
@@ -1444,9 +1444,9 @@ def view_widget(self, figure_size=(7, 7)):
         try:
             from menpowidgets import view_widget
             view_widget(self, figure_size=figure_size)
-        except ImportError:
+        except ImportError as e:
             from menpo.visualize.base import MenpowidgetsMissingError
-            raise MenpowidgetsMissingError()
+            raise MenpowidgetsMissingError(e.name)
 
     def __str__(self):
         str_out = 'PCA Model \n'                             \

diff --git a/menpo/shape/graph.py b/menpo/shape/graph.py
@@ -2363,9 +2363,9 @@ def _view_3d(self, figure_id=None, new_figure=True, render_lines=True,
                 render_numbering=render_numbering,
                 numbers_colour=numbers_colour, numbers_size=numbers_size)
             return renderer
-        except ImportError:
+        except ImportError as e:
             from menpo.visualize import Menpo3dMissingError
-            raise Menpo3dMissingError()
+            raise Menpo3dMissingError(e.name)
 
 
 class PointUndirectedGraph(PointGraph, UndirectedGraph):

diff --git a/menpo/shape/labelled.py b/menpo/shape/labelled.py
@@ -765,9 +765,9 @@ def _view_3d(self, with_labels=None, without_labels=None, group='group',
                 marker_colour=marker_colour, marker_resolution=marker_resolution,
                 step=step, alpha=alpha, render_numbering=render_numbering,
                 numbers_colour=numbers_colour, numbers_size=numbers_size)
-        except ImportError:
+        except ImportError as e:
             from menpo.visualize import Menpo3dMissingError
-            raise Menpo3dMissingError()
+            raise Menpo3dMissingError(e.name)
 
     @viewwrapper
     def view_widget(self, ):
@@ -791,9 +791,9 @@ def _view_widget_2d(self, figure_size=(7, 7)):
         try:
             from menpowidgets import view_widget
             view_widget(self, figure_size=figure_size)
-        except ImportError:
+        except ImportError as e:
             from menpo.visualize.base import MenpowidgetsMissingError
-            raise MenpowidgetsMissingError()
+            raise MenpowidgetsMissingError(e.name)
 
     def _view_widget_3d(self):
         r"""
@@ -803,9 +803,9 @@ def _view_widget_3d(self):
         try:
             from menpowidgets import view_widget
             view_widget(self)
-        except ImportError:
+        except ImportError as e:
             from menpo.visualize.base import MenpowidgetsMissingError
-            raise MenpowidgetsMissingError()
+            raise MenpowidgetsMissingError(e.name)
 
     def __str__(self):
         return '{}: n_labels: {}, n_points: {}, n_edges: {}'.format(

diff --git a/menpo/shape/mesh/base.py b/menpo/shape/mesh/base.py
@@ -1176,6 +1176,6 @@ def _view_3d(self, figure_id=None, new_figure=True, mesh_type='wireframe',
                 normals_marker_resolution=normals_marker_resolution,
                 normals_marker_size=normals_marker_size, step=step, alpha=alpha)
             return renderer
-        except ImportError:
+        except ImportError as e:
             from menpo.visualize import Menpo3dMissingError
-            raise Menpo3dMissingError()
+            raise Menpo3dMissingError(e.name)
diff --git a/menpo/shape/mesh/coloured.py b/menpo/shape/mesh/coloured.py
@@ -316,9 +316,9 @@ def _view_3d(self, figure_id=None, new_figure=True, render_texture=True,
                     normals_marker_size=normals_marker_size, step=step,
                     alpha=alpha)
                 return renderer
-            except ImportError:
+            except ImportError as e:
                 from menpo.visualize import Menpo3dMissingError
-                raise Menpo3dMissingError()
+                raise Menpo3dMissingError(e.name)
         else:
             try:
                 from menpo3d.visualize import TriMeshViewer3d
@@ -333,9 +333,9 @@ def _view_3d(self, figure_id=None, new_figure=True, render_texture=True,
                     normals_marker_size=normals_marker_size, step=step,
                     alpha=alpha)
                 return renderer
-            except ImportError:
+            except ImportError as e:
                 from menpo.visualize import Menpo3dMissingError
-                raise Menpo3dMissingError()
+                raise Menpo3dMissingError(e.name)
 
     def _view_2d(self, figure_id=None, new_figure=False, image_view=True,
                  render_lines=True, line_colour='r', line_style='-',

diff --git a/menpo/shape/mesh/textured.py b/menpo/shape/mesh/textured.py
@@ -368,9 +368,9 @@ def _view_3d(self, figure_id=None, new_figure=True, render_texture=True,
                     normals_marker_size=normals_marker_size, step=step,
                     alpha=alpha)
                 return renderer
-            except ImportError:
+            except ImportError as e:
                 from menpo.visualize import Menpo3dMissingError
-                raise Menpo3dMissingError()
+                raise Menpo3dMissingError(e.name)
         else:
             try:
                 from menpo3d.visualize import TriMeshViewer3d
@@ -385,9 +385,9 @@ def _view_3d(self, figure_id=None, new_figure=True, render_texture=True,
                     normals_marker_size=normals_marker_size, step=step,
                     alpha=alpha)
                 return renderer
-            except ImportError:
+            except ImportError as e:
                 from menpo.visualize import Menpo3dMissingError
-                raise Menpo3dMissingError()
+                raise Menpo3dMissingError(e.name)
 
     def _view_2d(self, figure_id=None, new_figure=False, image_view=True,
                  render_lines=True, line_colour='r', line_style='-',

diff --git a/menpo/shape/pointcloud.py b/menpo/shape/pointcloud.py
@@ -984,9 +984,9 @@ def _view_3d(self, figure_id=None, new_figure=True, render_markers=True,
                 step=step, alpha=alpha, render_numbering=render_numbering,
                 numbers_colour=numbers_colour, numbers_size=numbers_size)
             return renderer
-        except ImportError:
+        except ImportError as e:
             from menpo.visualize import Menpo3dMissingError
-            raise Menpo3dMissingError()
+            raise Menpo3dMissingError(e.name)
 
     def _view_landmarks_3d(self, group=None, with_labels=None,
                            without_labels=None, figure_id=None,
@@ -1121,9 +1121,9 @@ def _view_widget_2d(self, figure_size=(7, 7)):
         try:
             from menpowidgets import view_widget
             view_widget(self, figure_size=figure_size)
-        except ImportError:
+        except ImportError as e:
             from menpo.visualize.base import MenpowidgetsMissingError
-            raise MenpowidgetsMissingError()
+            raise MenpowidgetsMissingError(e.name)
 
     def _view_widget_3d(self):
         r"""
@@ -1132,9 +1132,9 @@ def _view_widget_3d(self):
         try:
             from menpowidgets import view_widget
             view_widget(self)
-        except ImportError:
+        except ImportError as e:
             from menpo.visualize.base import MenpowidgetsMissingError
-            raise MenpowidgetsMissingError()
+            raise MenpowidgetsMissingError(e.name)
 
     def _transform_self_inplace(self, transform):
         self.points = transform(self.points)

diff --git a/menpo/visualize/base.py b/menpo/visualize/base.py
@@ -9,17 +9,21 @@ class Menpo3dMissingError(MenpoMissingDependencyError):
     Exception that is thrown when an attempt is made to import a 3D
     visualisation method, but 'menpo3d' is not installed.
     """
-    def __init__(self):
-        super(Menpo3dMissingError, self).__init__('menpo3d')
+    def __init__(self, actual_missing_import_name):
+        super(Menpo3dMissingError, self).__init__(actual_missing_import_name)
+        self.message += ("\nThis import is required in order to use the "
+                         "'menpo3d' package")
 
 
 class MenpowidgetsMissingError(MenpoMissingDependencyError):
     r"""
     Exception that is thrown when an attempt is made to import a widget, but
     'menpowidgets' is not installed.
     """
-    def __init__(self):
-        super(MenpowidgetsMissingError, self).__init__('menpowidgets')
+    def __init__(self, actual_missing_import_name):
+        super(MenpowidgetsMissingError, self).__init__(actual_missing_import_name)
+        self.message += ("\nThis import is required in order to use the "
+                         "'menpowidgets' package")
 
 
 class Renderer(object):