Merge pull request #37 from Ultimaker/fix/typing-in-comment-backward-compatibility

Python 3.4, print-cluster, backward compatibility

Author: Xiaozhou Li

Charon/filetypes/OpenPackagingConvention.py

@@ -25,7 +25,7 @@ class OpenPackagingConvention(FileInterface):
     _global_metadata_file = "/Metadata/OPC_Global.json"  # Where the global metadata file is.
     _opc_metadata_relationship_type = "http://schemas.ultimaker.org/package/2018/relationships/opc_metadata"  # Unique identifier of the relationship type that relates OPC metadata to files.
     _metadata_prefix = "/metadata"
-    _aliases:Dict[str, str] = OrderedDict([])  # A standard OPC file doest not have default aliases. These must be implemented in inherited classes.
+    _aliases = OrderedDict([])  # type: Dict[str, str]  # A standard OPC file doest not have default aliases. These must be implemented in inherited classes.
 
     mime_type = "application/x-opc"
 
@@ -299,7 +299,7 @@ def _processAliases(self, virtual_path: str) -> str:
         # Replace all aliases.
         for regex, replacement in self._aliases.items():
             if regex.startswith("/"):
-                expression = rf"^{regex}"
+                expression = r"^" + regex
             else:
                 expression = regex
             virtual_path = re.sub(expression, replacement, virtual_path)

mypy.ini

@@ -1,4 +1,5 @@
 [mypy]
+python_version = 3.4
 disallow_untyped_calls = False
 disallow_untyped_defs = False
 disallow_incomplete_defs = False