pass on import error when testing sankey

docs/source/examples/performance_modeling.py

@@ -242,9 +242,11 @@ def setup(self):
 sol = M.solve(verbosity=0)
 print(sol.diff("solution.pkl", showvars=vars_of_interest, sortbymodel=False))
 
-# this will only make an image when run in jupyter notebook
-# from gpkit.interactive.sankey import Sankey
-from gpkit.interactive.sankey import Sankey
-variablesankey = Sankey(sol, M).diagram(AC.wing.A)
-sankey = Sankey(sol, M).diagram(width=1200, height=400, maxlinks=30)
-sankey  # pylint: disable=pointless-statement
+try:
+    from gpkit.interactive.sankey import Sankey
+    variablesankey = Sankey(sol, M).diagram(AC.wing.A)
+    sankey = Sankey(sol, M).diagram(width=1200, height=400, maxlinks=30)
+    # the line below shows an interactive graph if run in jupyter notebook
+    sankey  # pylint: disable=pointless-statement
+except (ImportError, ModuleNotFoundError):
+    print("Making Sankey diagrams requires the ipysankeywidget package")

gpkit/solution_array.py

@@ -377,7 +377,7 @@ def almost_equal(self, other, reltol=1e-3, sens_abstol=0.01):
     def diff(self, other, showvars=None, *,
              constraintsdiff=True, senssdiff=False, sensstol=0.1,
              absdiff=False, abstol=0, reldiff=True, reltol=1.0,
-             sortmodelsbysenss= True, **tableargs):
+             sortmodelsbysenss=True, **tableargs):
         """Outputs differences between this solution and another
 
         Arguments