Enable deepcopy for ExpData(View) (#2196)

Fixes a bug in `SwigPtrView.__deepcopy__` which did not produce a deep copy.

Add `SwigPtrView.__eq__` to allow for comparison. The view objects are considered equal if the underlying viewed objects are equal.

Fixes #2189.

Author: dweindl

python/sdist/amici/numpy.py

@@ -137,7 +137,8 @@ def __deepcopy__(self, memo):
 
         :returns: SwigPtrView deep copy
         """
-        other = SwigPtrView(self._swigptr)
+        # We assume we have a copy-ctor for the swigptr object
+        other = self.__class__(copy.deepcopy(self._swigptr))
         other._field_names = copy.deepcopy(self._field_names)
         other._field_dimensions = copy.deepcopy(self._field_dimensions)
         other._cache = copy.deepcopy(self._cache)
@@ -151,6 +152,18 @@ def __repr__(self):
         """
         return f"<{self.__class__.__name__}({self._swigptr})>"
 
+    def __eq__(self, other):
+        """
+        Equality check
+
+        :param other: other object
+
+        :returns: whether other object is equal to this object
+        """
+        if not isinstance(other, self.__class__):
+            return False
+        return self._swigptr == other._swigptr
+
 
 class ReturnDataView(SwigPtrView):
     """
@@ -344,6 +357,9 @@ class ExpDataView(SwigPtrView):
     """
     Interface class for C++ Exp Data objects that avoids possibly costly
     copies of member data.
+
+    NOTE: This currently assumes that the underlying :class:`ExpData`
+    does not change after instantiating an :class:`ExpDataView`.
     """
 
     _field_names = [

python/tests/test_swig_interface.py

@@ -7,6 +7,7 @@
 import numbers
 
 import amici
+import numpy as np
 
 
 def test_version_number(pysb_example_presimulation_module):
@@ -451,3 +452,21 @@ def test_edata_equality_operator():
     # check that comparison with other types works
     # this is not implemented by swig by default
     assert e1 != 1
+
+
+def test_expdata_and_expdataview_are_deepcopyable():
+    edata1 = amici.ExpData(3, 2, 3, range(4))
+    edata1.setObservedData(np.zeros((3, 4)).flatten())
+
+    # ExpData
+    edata2 = copy.deepcopy(edata1)
+    assert edata1 == edata2
+    assert edata1.this != edata2.this
+    edata2.setTimepoints([0])
+    assert edata1 != edata2
+
+    # ExpDataView
+    ev1 = amici.ExpDataView(edata1)
+    ev2 = copy.deepcopy(ev1)
+    assert ev2._swigptr.this != ev1._swigptr.this
+    assert ev1 == ev2

swig/edata.i

@@ -77,6 +77,11 @@ def __repr__(self):
 
 def __eq__(self, other):
     return other.__class__ == self.__class__ and __eq__(self, other)
+
+def __deepcopy__(self, memo):
+    # invoke copy constructor
+    return type(self)(self)
+
 %}
 };
 %extend std::unique_ptr<amici::ExpData> {