fix repr of Model with no process

Author: benbovy

xsimlab/model.py

@@ -355,9 +355,12 @@ def drop_processes(self, keys):
     def __repr__(self):
         n_inputs = sum([len(v) for v in self._input_vars.values()])
 
-        hdr = ("<xsimlab.Model (%d processes, %d inputs)>\n"
+        hdr = ("<xsimlab.Model (%d processes, %d inputs)>"
                % (len(self._processes), n_inputs))
 
+        if not len(self._processes):
+            return hdr
+
         max_line_length = 70
         col_width = max([_calculate_col_width(var)
                          for var in self._input_vars.values()])
@@ -378,4 +381,4 @@ def __repr__(self):
                 proc_str += '\n' + '\n'.join(lines)
             blocks.append(proc_str)
 
-        return hdr + '\n'.join(blocks)
+        return hdr + '\n' + '\n'.join(blocks)

xsimlab/tests/test_model.py

@@ -157,3 +157,6 @@ def test_drop_processes(self, model):
 
     def test_repr(self, model, model_repr):
         assert repr(model) == model_repr
+
+        expected = "<xsimlab.Model (0 processes, 0 inputs)>"
+        assert repr(Model({})) == expected