Fix basic pickling

param/parameterized.py

@@ -694,24 +694,30 @@ def _skip_event(*events, **kwargs):
     return True
 
 
+# Two callers at the module top level to support pickling.
+async def _async_caller(*events, what='value', changed=None, callback=None, function=None):
+    if callback:
+        callback(*events)
+    if not _skip_event or not _skip_event(*events, what=what, changed=changed):
+        await function()
+
+
+def _sync_caller(*events, what='value', changed=None, callback=None, function=None):
+    if callback:
+        callback(*events)
+    if not _skip_event(*events, what=what, changed=changed):
+        return function()
+
+
 def _m_caller(self, method_name, what='value', changed=None, callback=None):
     """
     Wraps a method call adding support for scheduling a callback
     before it is executed and skipping events if a subobject has
     changed but its values have not.
     """
     function = getattr(self, method_name)
-    if iscoroutinefunction(function):
-        async def caller(*events):
-            if callback:
-                callback(*events)
-            if not _skip_event or not _skip_event(*events, what=what, changed=changed):
-                await function()
-    else:
-        def caller(*events):
-            if callback: callback(*events)
-            if not _skip_event(*events, what=what, changed=changed):
-                return function()
+    _caller = _async_caller if iscoroutinefunction(function) else _sync_caller
+    caller = partial(_caller, what=what, changed=changed, callback=callback, function=function)
     caller._watcher_name = method_name
     return caller
 
@@ -1698,7 +1704,8 @@ def self_or_cls(self_):
 
     def __setstate__(self, state):
         # Set old parameters state on Parameterized._parameters_state
-        self_or_cls = state.get('self', state.get('cls'))
+        self_, cls = state.get('self'), state.get('cls')
+        self_or_cls = self_ if self_ is not None else cls
         for k in self_or_cls._parameters_state:
             key = '_'+k
             if key in state:

pyproject.toml

@@ -68,6 +68,8 @@ tests-full = [
     "ipython",
     "jsonschema",
     "gmpy",
+    "cloudpickle",
+    "nest_asyncio",
 ]
 lint = [
     "flake8",
@@ -121,6 +123,8 @@ dependencies = [
     "jsonschema",
     "numpy",
     "pandas",
+    "cloudpickle",
+    "nest_asyncio",
     # To keep __version__ up-to-date in editable installs
     "setuptools_scm",
 ]
@@ -179,6 +183,8 @@ name."^(?!pypy).*".dependencies = [
     "odfpy",
     "feather-format",
     "pyarrow",
+    "cloudpickle",
+    "nest_asyncio",
 ]
 # Only install gmpy on Linux on these version
 # Only install tables (deser HDF5) on Linux on these version