[Cython] Retain units info when converting AnyMap to Python

include/cantera/base/AnyMap.h

@@ -621,6 +621,9 @@ class AnyMap : public AnyBase
     //! Return the default units that should be used to convert stored values
     const UnitSystem& units() const { return *m_units; }
 
+    //! @copydoc units()
+    shared_ptr<UnitSystem> unitsShared() const { return m_units; }
+
     //! Use the supplied UnitSystem to set the default units, and recursively
     //! process overrides from nodes named `units`.
     /*!

interfaces/cython/cantera/_utils.pxd

@@ -7,6 +7,7 @@
 from libcpp.unordered_map cimport unordered_map
 
 from .ctcxx cimport *
+from .units cimport UnitSystem
 
 cdef extern from "cantera/base/AnyMap.h" namespace "Cantera":
     cdef cppclass CxxAnyValue "Cantera::AnyValue"
@@ -37,6 +38,7 @@ cdef extern from "cantera/base/AnyMap.h" namespace "Cantera":
         void update(CxxAnyMap& other, cbool)
         string keys_str()
         void applyUnits()
+        shared_ptr[CxxUnitSystem] unitsShared()
 
     cdef cppclass CxxAnyValue "Cantera::AnyValue":
         CxxAnyValue()
@@ -86,14 +88,17 @@ cdef extern from "cantera/cython/utils_utils.h":
 
     cdef void CxxSetLogger "setLogger" (CxxPythonLogger*)
 
+cdef class AnyMap(dict):
+    cdef _set_CxxUnitSystem(self, shared_ptr[CxxUnitSystem] units)
+    cdef UnitSystem unitsystem
 
 cdef string stringify(x) except *
 cdef pystr(string x)
 
 cdef comp_map_to_dict(Composition m)
 cdef Composition comp_map(X) except *
 
-cdef CxxAnyMap dict_to_anymap(dict data, cbool hyphenize=*) except *
+cdef CxxAnyMap dict_to_anymap(data, cbool hyphenize=*) except *
 cdef anymap_to_dict(CxxAnyMap& m)
 
 cdef CxxAnyValue python_to_anyvalue(item, name=*) except *

interfaces/cython/cantera/_utils.pyx

@@ -153,6 +153,18 @@ class CanteraError(RuntimeError):
 
 cdef public PyObject* pyCanteraError = <PyObject*>CanteraError
 
+
+cdef class AnyMap(dict):
+    def __cinit__(self, *args, **kwawrgs):
+        self.unitsystem = UnitSystem()
+
+    cdef _set_CxxUnitSystem(self, shared_ptr[CxxUnitSystem] units):
+        self.unitsystem._set_unitSystem(units)
+
+    def default_units(self):
+        return self.unitsystem.defaults()
+
+
 cdef anyvalue_to_python(string name, CxxAnyValue& v):
     cdef CxxAnyMap a
     cdef CxxAnyValue b
@@ -207,12 +219,14 @@ cdef anyvalue_to_python(string name, CxxAnyValue& v):
 cdef anymap_to_dict(CxxAnyMap& m):
     cdef pair[string,CxxAnyValue] item
     m.applyUnits()
-    if m.empty():
-        return {}
-    return {pystr(item.first): anyvalue_to_python(item.first, item.second)
-            for item in m.ordered()}
+    cdef AnyMap out = AnyMap()
+    out._set_CxxUnitSystem(m.unitsShared())
+    for item in m.ordered():
+        out[pystr(item.first)] = anyvalue_to_python(item.first, item.second)
+    return out
+
 
-cdef CxxAnyMap dict_to_anymap(dict data, cbool hyphenize=False) except *:
+cdef CxxAnyMap dict_to_anymap(data, cbool hyphenize=False) except *:
     cdef CxxAnyMap m
     if hyphenize:
         # replace "_" by "-": while Python dictionaries typically use "_" in key names,

interfaces/cython/cantera/reaction.pyx

@@ -221,7 +221,7 @@ cdef class ArrheniusRate(ArrheniusRateBase):
         if init:
             self._cinit(input_data, A=A, b=b, Ea=Ea)
 
-    def _from_dict(self, dict input_data):
+    def _from_dict(self, input_data):
         self._rate.reset(new CxxArrheniusRate(dict_to_anymap(input_data)))
 
     def _from_parameters(self, A, b, Ea):
@@ -248,7 +248,7 @@ cdef class BlowersMaselRate(ArrheniusRateBase):
         if init:
             self._cinit(input_data, A=A, b=b, Ea0=Ea0, w=w)
 
-    def _from_dict(self, dict input_data):
+    def _from_dict(self, input_data):
         self._rate.reset(new CxxBlowersMaselRate(dict_to_anymap(input_data)))
 
     def _from_parameters(self, A, b, Ea0, w):
@@ -321,7 +321,7 @@ cdef class TwoTempPlasmaRate(ArrheniusRateBase):
         """
         return self.rate.eval(temperature, elec_temp)
 
-    def _from_dict(self, dict input_data):
+    def _from_dict(self, input_data):
         self._rate.reset(
             new CxxTwoTempPlasmaRate(dict_to_anymap(input_data, hyphenize=True))
         )
@@ -448,7 +448,7 @@ cdef class LindemannRate(FalloffRate):
     """
     _reaction_rate_type = "Lindemann"
 
-    def _from_dict(self, dict input_data):
+    def _from_dict(self, input_data):
         self._rate.reset(
             new CxxLindemannRate(dict_to_anymap(input_data, hyphenize=True))
         )
@@ -468,7 +468,7 @@ cdef class TroeRate(FalloffRate):
     """
     _reaction_rate_type = "Troe"
 
-    def _from_dict(self, dict input_data):
+    def _from_dict(self, input_data):
         self._rate.reset(
             new CxxTroeRate(dict_to_anymap(input_data, hyphenize=True))
         )
@@ -488,7 +488,7 @@ cdef class SriRate(FalloffRate):
     """
     _reaction_rate_type = "SRI"
 
-    def _from_dict(self, dict input_data):
+    def _from_dict(self, input_data):
         self._rate.reset(
             new CxxSriRate(dict_to_anymap(input_data, hyphenize=True))
         )
@@ -504,7 +504,7 @@ cdef class TsangRate(FalloffRate):
     """
     _reaction_rate_type = "Tsang"
 
-    def _from_dict(self, dict input_data):
+    def _from_dict(self, input_data):
         self._rate.reset(
             new CxxTsangRate(dict_to_anymap(input_data, hyphenize=True))
         )
@@ -834,7 +834,7 @@ cdef class InterfaceRateBase(ArrheniusRateBase):
             cdef CxxAnyMap cxx_deps
             self.interface.getCoverageDependencies(cxx_deps)
             return anymap_to_dict(cxx_deps)
-        def __set__(self, dict deps):
+        def __set__(self, deps):
             cdef CxxAnyMap cxx_deps = dict_to_anymap(deps)
 
             self.interface.setCoverageDependencies(cxx_deps)
@@ -892,7 +892,7 @@ cdef class InterfaceArrheniusRate(InterfaceRateBase):
         if init:
             self._cinit(input_data, A=A, b=b, Ea=Ea)
 
-    def _from_dict(self, dict input_data):
+    def _from_dict(self, input_data):
         self._rate.reset(new CxxInterfaceArrheniusRate(dict_to_anymap(input_data)))
 
     def _from_parameters(self, A, b, Ea):
@@ -920,7 +920,7 @@ cdef class InterfaceBlowersMaselRate(InterfaceRateBase):
         if init:
             self._cinit(input_data, A=A, b=b, Ea0=Ea0, w=w)
 
-    def _from_dict(self, dict input_data):
+    def _from_dict(self, input_data):
         self._rate.reset(new CxxInterfaceBlowersMaselRate(dict_to_anymap(input_data)))
 
     def _from_parameters(self, A, b, Ea0, w):
@@ -1030,7 +1030,7 @@ cdef class StickingArrheniusRate(StickRateBase):
         if init:
             self._cinit(input_data, A=A, b=b, Ea=Ea)
 
-    def _from_dict(self, dict input_data):
+    def _from_dict(self, input_data):
         self._rate.reset(new CxxStickingArrheniusRate(dict_to_anymap(input_data)))
 
     def _from_parameters(self, A, b, Ea):
@@ -1057,7 +1057,7 @@ cdef class StickingBlowersMaselRate(StickRateBase):
         if init:
             self._cinit(input_data, A=A, b=b, Ea0=Ea0, w=w)
 
-    def _from_dict(self, dict input_data):
+    def _from_dict(self, input_data):
         self._rate.reset(new CxxStickingBlowersMaselRate(dict_to_anymap(input_data)))
 
     def _from_parameters(self, A, b, Ea0, w):

interfaces/cython/cantera/units.pxd

@@ -34,4 +34,6 @@ cdef class Units:
     cdef copy(CxxUnits)
 
 cdef class UnitSystem:
-    cdef CxxUnitSystem unitsystem
+    cdef _set_unitSystem(self, shared_ptr[CxxUnitSystem] units)
+    cdef shared_ptr[CxxUnitSystem] _unitsystem
+    cdef CxxUnitSystem* unitsystem

interfaces/cython/cantera/units.pyx

@@ -94,13 +94,21 @@ cdef class UnitSystem:
         ct.UnitSystem()
     """
     def __cinit__(self, units=None):
-        self.unitsystem = CxxUnitSystem()
+        self._unitsystem.reset(new CxxUnitSystem())
+        self.unitsystem = self._unitsystem.get()
         if units:
             self.units = units
 
     def __repr__(self):
         return f"<UnitSystem at {id(self):0x}>"
 
+    cdef _set_unitSystem(self, shared_ptr[CxxUnitSystem] units):
+        self._unitsystem = units
+        self.unitsystem = self._unitsystem.get()
+
+    def defaults(self):
+        return self.unitsystem.defaults()
+
     property units:
         """
         Units used by the unit system

interfaces/cython/cantera/yamlwriter.pxd

@@ -24,4 +24,4 @@ cdef class YamlWriter:
     cdef shared_ptr[CxxYamlWriter] _writer
     cdef CxxYamlWriter* writer
     @staticmethod
-    cdef CxxUnitSystem _get_unitsystem(UnitSystem units)
+    cdef shared_ptr[CxxUnitSystem] _get_unitsystem(UnitSystem units)

interfaces/cython/cantera/yamlwriter.pyx

@@ -3,6 +3,7 @@
 
 from .solutionbase cimport *
 from ._utils cimport *
+from cython.operator import dereference as deref
 
 cdef class YamlWriter:
     """
@@ -64,12 +65,11 @@ cdef class YamlWriter:
         def __set__(self, units):
             if not isinstance(units, UnitSystem):
                 units = UnitSystem(units)
-            cdef CxxUnitSystem cxxunits = YamlWriter._get_unitsystem(units)
-            self.writer.setUnitSystem(cxxunits)
+            self.writer.setUnitSystem(deref(YamlWriter._get_unitsystem(units).get()))
 
     @staticmethod
-    cdef CxxUnitSystem _get_unitsystem(UnitSystem units):
-        return units.unitsystem
+    cdef shared_ptr[CxxUnitSystem] _get_unitsystem(UnitSystem units):
+        return units._unitsystem
 
     def __reduce__(self):
         raise NotImplementedError('YamlWriter object is not picklable')