Merge pull request #85 from LSSTDESC/fix_list_param

fix for list type config params

ceci/stage.py

@@ -490,6 +490,7 @@ def parse_command_line(cls, cmd=None):
         for conf, def_val in cls.config_options.items():
             if isinstance(def_val, StageParameter):
                 opt_type = def_val.dtype
+                def_val = def_val.default
             else:
                 opt_type = def_val if isinstance(def_val, type) else type(def_val)
             if opt_type == bool:
@@ -498,9 +499,12 @@ def parse_command_line(cls, cmd=None):
                     f"--no-{conf}", dest=conf, action="store_const", const=False
                 )
             elif opt_type == list:
-                out_type = (
-                    def_val[0] if isinstance(def_val[0], type) else type(def_val[0])
-                )
+                if not def_val:
+                    out_type = str
+                else:
+                    out_type = (
+                        def_val[0] if isinstance(def_val[0], type) else type(def_val[0])
+                    )
                 if out_type is str:  # pragma: no cover
                     parser.add_argument(
                         f"--{conf}", type=lambda string: string.split(",")

tests/test_stage.py

@@ -131,6 +131,8 @@ class TestStage(PipelineStage):
         config_options = dict(
             a=StageParameter(float, 5., msg="a float"),
             b=StageParameter(str, msg="a str"),
+            c=StageParameter(list, [1,2,3], msg="a list"),
+            d=StageParameter(list, [], msg="an empty list"),
         )
 
         def run(self):
@@ -141,7 +143,9 @@ def run(self):
         )
     assert stage_1.config.a == 6.
     assert stage_1.config.b == 'puffins are not extinct?'
-
+    assert 1 in stage_1.config.c
+    assert len(stage_1.config.d) == 0
+
     cmd = "TestStage", "--a", "6", "--b", "puffins are not extinct?", "--inp", "dummy"
     stage_1_cmd = TestStage(TestStage.parse_command_line(cmd))
     assert stage_1_cmd.config.a == 6.