Expose cvxpy DCP trace in case of error (#173)

pypfopt/base_optimizer.py

@@ -215,8 +215,8 @@ class BaseConvexOptimizer(BaseOptimizer):
                 opt.solve(solver=self.solver, verbose=True)
             else:
                 opt.solve()
-        except (TypeError, cp.DCPError):
-            raise exceptions.OptimizationError
+        except (TypeError, cp.DCPError) as e:
+            raise exceptions.OptimizationError from e
         if opt.status != "optimal":
             raise exceptions.OptimizationError
         self.weights = self._w.value.round(16) + 0.0  # +0.0 removes signed zero

pypfopt/exceptions.py

@@ -3,7 +3,6 @@ The ``exceptions`` module houses custom exceptions. Currently implemented:
 
 - OptimizationError
 """
-import traceback
 
 
 class OptimizationError(Exception):
@@ -16,9 +15,4 @@ class OptimizationError(Exception):
         default_message = (
             "Please check your objectives/constraints or use a different solver."
         )
-
-        if not (args or kwargs):
-            args = (default_message,)
-        super().__init__(*args, **kwargs)
-
-        traceback.print_exc()
+        super().__init__(default_message, *args, **kwargs)