Handle a mix of [_-] in datestring regex

Author: jtroberts

bin/vizgen.py

@@ -247,7 +247,7 @@ def create_mrf(input_files, config, layer_name, colormap, empty_tile):
         print('Generating MRF config ' + mrf_config)
         with open(mrf_config, 'w') as conf:
             xml = MRF_CONFIG_TEMPLATE
-            match = re.findall(r'(\d{4}-\d{2,}-\d{2,})|(\d{4}-\d{2,})', str(filename))
+            match = re.findall(r'(\d{4}[_-]\d{2,}[_-]\d{2,})|(\d{4}[_-]\d{2,})', str(filename))
             if len(match) > 0:
                 for m in match[0]:
                     if m != '':