Proper assert when a molecule of interest was not found

command_line/cadbiom_cmd/interaction_graph.py

@@ -215,6 +215,8 @@ def filter_trajectories(trajectories, molecules_of_interest):
     filtered_macs = tuple(sol for sol, trajectory_places in trajectories
                           if entity_is_in_trajectory(sol, trajectory_places))
 
+    assert filtered_macs, "No molecule of interest was found."
+
     return filtered_macs, binary_interactions
 
 
@@ -342,7 +344,8 @@ def build_interactions(filtered_macs, binary_interactions):
          for data in binary_interactions.iteritems())
     # warning: marchera pas si la molec of interest est dans les conditions
     # et non dans les places des trajectoires...
-    molecule_stimuli_interactions = Counter(next(g))
+    # => Comme si la molecule n'était pas trouvée
+    molecule_stimuli_interactions = Counter()
     [molecule_stimuli_interactions.update(f_bin) for f_bin in g]
 
     return all_genes, all_stimuli, genes_interactions, \