Fix splinepy #327

gustaf/_base.py

@@ -10,7 +10,7 @@ class GustafBase:
     methods are defined as classmethods..
     """
 
-    __slots__ = ()
+    __slots__ = ("__weakref__",)
 
     def __init_subclass__(cls, *args, **kwargs):
         """

gustaf/helpers/__init__.py

@@ -1,7 +1,8 @@
-from gustaf.helpers import data, options, raise_if
+from gustaf.helpers import _base, data, options, raise_if
 
 __all__ = [
     "data",
     "options",
     "raise_if",
+    "_base",
 ]

gustaf/helpers/_base.py

@@ -0,0 +1,29 @@
+"""gustaf/gustaf/helpers/_base.py
+
+Base class for helper
+"""
+
+from weakref import ref
+
+from gustaf._base import GustafBase
+
+
+class HelperBase(GustafBase):
+    """
+    Minimal base layer for helper classes to avoid cyclic referencing.
+    Instead of saving a pure reference to helpee object, this will create a
+    weakref instead. This class defines `_helpee` setters and getters, so that
+    existing code can remain untouched.
+    """
+
+    __slots__ = ("_helpee_weak_ref",)
+
+    @property
+    def _helpee(self):
+        """Returns dereferenced weak ref. Setter will create and save weakref
+        of a helpee."""
+        return self._helpee_weak_ref()
+
+    @_helpee.setter
+    def _helpee(self, helpee):
+        self._helpee_weak_ref = ref(helpee)

gustaf/helpers/data.py

@@ -9,7 +9,7 @@
 
 import numpy as np
 
-from gustaf._base import GustafBase
+from gustaf.helpers._base import HelperBase
 
 
 class TrackedArray(np.ndarray):
@@ -195,11 +195,8 @@ def make_tracked_array(array, dtype=None, copy=True):
     return tracked
 
 
-class DataHolder(GustafBase):
-    __slots__ = (
-        "_helpee",
-        "_saved",
-    )
+class DataHolder(HelperBase):
+    __slots__ = ("_saved",)
 
     def __init__(self, helpee):
         """Base class for any data holder. Behaves similar to dict.

gustaf/helpers/options.py

@@ -4,6 +4,7 @@
 """
 from copy import deepcopy
 
+from gustaf.helpers._base import HelperBase
 from gustaf.helpers.raise_if import ModuleImportRaiser
 
 
@@ -224,7 +225,7 @@ def make_valid_options(*options):
     return valid_options
 
 
-class ShowOption:
+class ShowOption(HelperBase):
     """
     Behaves similar to dict, but will only accept a set of options that's
     applicable to the helpee class. Intended use is to create a
@@ -234,7 +235,7 @@ class ShowOption:
     specific common routines. ShowOption and ShowManager in a sense.
     """
 
-    __slots__ = ("_helpee", "_options")
+    __slots__ = ("_options",)
 
     _valid_options = {}