Implement the PEP 302 protocol for get_filename() as

importlib.abc.ExecutionLoader. PyLoader now inherits from this ABC instead of
InspectLoader directly. Both PyLoader and PyPycLoader provide concrete
implementations of get_filename in terms of source_path and bytecode_path.

1 files changed, 17 insertions, 1 deletions

diff --git a/Lib/importlib/abc.py b/Lib/importlib/abc.py
index 7b89d0b..c912280 100644
--- a/Lib/importlib/abc.py
+++ b/Lib/importlib/abc.py
@@ -76,7 +76,23 @@ InspectLoader.register(machinery.BuiltinImporter)
 InspectLoader.register(machinery.FrozenImporter)
 
 
-class PyLoader(_bootstrap.PyLoader, ResourceLoader, InspectLoader):
+class ExecutionLoader(InspectLoader):
+
+    """Abstract base class for loaders that wish to support the execution of
+    modules as scripts.
+
+    This ABC represents one of the optional protocols specified in PEP 302.
+
+    """
+
+    @abc.abstractmethod
+    def get_filename(self, fullname:str) -> str:
+        """Abstract method which should return the value that __file__ is to be
+        set to."""
+        raise NotImplementedError
+
+
+class PyLoader(_bootstrap.PyLoader, ResourceLoader, ExecutionLoader):
 
     """Abstract base class to assist in loading source code by requiring only
     back-end storage methods to be implemented.