Remove flag day change

Author: JDBetteridge

firedrake/__init__.py

@@ -127,9 +127,11 @@
 set_log_handlers(comm=COMM_WORLD)
 
 # Moved functionality
-from firedrake._deprecation import output, plot
-sys.modules["firedrake.output"] = output
-from firedrake.output import *
+from firedrake._deprecation import plot, File  # noqa: F401
+# Once `File` is deprecated update the above line removing `File` and add
+#   from firedrake._deprecation import output
+#   sys.modules["firedrake.output"] = output
+#   from firedrake.output import *
 sys.modules["firedrake.plot"] = plot
 from firedrake.plot import *
 

firedrake/_deprecation.py

@@ -2,6 +2,8 @@
 """
 import importlib
 
+from warnings import warn
+
 
 class _fake_module:
     """ Object which behaves like a module
@@ -52,6 +54,21 @@ def __call__(*args, **kwargs):
     ["VTKFile",]
 )
 
+
+# I hate it
+def File(*args, **kwargs):
+    """Deprecated File constructor.
+
+    Use `VTKFile` from `firedrake.output` instead
+    """
+    from .output import VTKFile
+    warn(
+        "The use of `File` for output is deprecated, please update your "
+        "code to use `VTKFile` from `firedrake.output`."
+    )
+    return VTKFile(*args, **kwargs)
+
+
 # Deprecate plotting in the global namespace
 plot = _fake_module(
     "firedrake.pyplot",