Config: disentangle changes to config and final evaluation in expconfig

expconfig.py

@@ -543,19 +543,6 @@ class ExpConfig(ConfigObj):
         if not getexp:
             pre_config['VERSIONS_'] = config_versions
 
-        # Re-read merged config with interpolation set.
-        # This works around incomprehensible inheritance of interpolation with
-        # merge. Make sure that all values are interpolated
-
-        config_lines = io.BytesIO()
-
-        pre_config.write(config_lines)
-        pre_config = None
-
-        config_lines.seek(0)
-        pre_config = ConfigObj(io.TextIOWrapper(config_lines),
-                               interpolation=False if getexp else 'template')
-
         # Extract experiment description from initial comment
         # if not set explicitly
         if 'EXP_DESCRIPTION' not in pre_config:
@@ -574,6 +561,23 @@ class ExpConfig(ConfigObj):
                 ))
             )
 
+        # Additional experiment info
+        self.experiment_id = pre_config[ExpConfig.id_name]
+        self.experiment_kind = re.sub(r'-\w+$', '', experiment_type)
+
+        # Re-read merged config with interpolation set.
+        # This works around incomprehensible inheritance of interpolation with
+        # merge. Make sure that all values are interpolated
+
+        config_lines = io.BytesIO()
+
+        pre_config.write(config_lines)
+        pre_config = None
+
+        config_lines.seek(0)
+        pre_config = ConfigObj(io.TextIOWrapper(config_lines),
+                               interpolation=False if getexp else 'template')
+
         pre_config.walk(eval_key)
 
         # Re-read final config without interpolation.
@@ -588,7 +592,4 @@ class ExpConfig(ConfigObj):
         ConfigObj.__init__(self, io.TextIOWrapper(config_lines),
                            interpolation=False)
         self.walk(uneval_key)
-        
-        self.experiment_id = self[ExpConfig.id_name]
-        self.experiment_kind = re.sub(r'-\w+$', '', experiment_type)