[WIP] fix for figure factory import when scipy not installed (#1423)

Fix for figure factory import when scipy not installed

plotly/figure_factory/__init__.py

@@ -3,7 +3,11 @@
 from plotly import optional_imports
 
 # Require that numpy exists for figure_factory
-import numpy
+np = optional_imports.get_module('numpy')
+if np is None:
+    raise ImportError("""\
+The figure factory module requires the numpy package""")
+
 
 from plotly.figure_factory._2d_density import create_2d_density
 from plotly.figure_factory._annotated_heatmap import create_annotated_heatmap

plotly/figure_factory/_ternary_contour.py

@@ -1,8 +1,9 @@
 from __future__ import absolute_import
-import numpy as np
-from scipy.interpolate import griddata
+from plotly import optional_imports
 from plotly.graph_objs import graph_objs as go
-import warnings
+
+import numpy as np
+interpolate = optional_imports.get_module('scipy.interpolate')
 
 
 def _pl_deep():
@@ -415,8 +416,8 @@ def _compute_grid(coordinates, values, tooltip_mode):
     gr_x = np.linspace(x_min, x_max, n_interp)
     gr_y = np.linspace(y_min, y_max, n_interp)
     grid_x, grid_y = np.meshgrid(gr_x, gr_y)
-    grid_z = griddata(cartes_coord_points[:2].T, values, (grid_x, grid_y),
-                      method='cubic')
+    grid_z = interpolate.griddata(
+        cartes_coord_points[:2].T, values, (grid_x, grid_y), method='cubic')
     bar_coords = np.einsum('ik, kmn -> imn', invM,
                            np.stack((grid_x, grid_y, np.ones(grid_x.shape))))
     # invalidate the points outside of the reference triangle
@@ -495,6 +496,10 @@ def create_ternary_contour(coordinates, values, pole_labels=['a', 'b', 'c'],
 
     fig = ff.create_ternary_contour(np.stack((a, b)), z, coloring='lines')
     """
+    if interpolate is None:
+        raise ImportError("""\
+The create_ternary_contour figure factory requires the scipy package""")
+
     grid_z, gr_x, gr_y, tooltip = _compute_grid(coordinates, values,
                                                 tooltip_mode)