better metadata rebuild method

doc/long_vignettes/tskitconvert_vignette.md

@@ -159,9 +159,14 @@ We can pass the `params` object on when exporting the data to `tskit`:
 ```{code-cell} python
 ts = pop.dump_tables_to_tskit(model_params=params)
 def rebuild_params(md):
+    import copy
+    import inspect
     import fwdpy11
+    md = copy.deepcopy(md)
     for i in dir(fwdpy11):
-        exec(f"from fwdpy11 import {i}")
+        if md.find(i) > 0:
+            if inspect.isclass(eval(f"fwdpy11.{i}")):
+                md = md.replace(i, "fwdpy11." + i)
     recovered_params = fwdpy11.ModelParams(**eval(md)) 
     return recovered_params
 recovered_params = rebuild_params(ts.metadata["model_params"])

tests/test_metadata_roundtrips_via_simulation.py

@@ -201,11 +201,16 @@ def test_metadata_roundtrip_single_deme_sim_with_parameters(rng, pdict, pop, inc
     provenance = json.loads(ts.provenance(0).record)
 
     def rebuild_pdict(provenance):
+        import copy
         import fwdpy11
+        import inspect
 
+        params = copy.deepcopy(provenance["parameters"]["params_dict"])
         for i in dir(fwdpy11):
-            exec(f"from fwdpy11 import {i}")
-        params_dict = eval(provenance["parameters"]["params_dict"])
+            if params.find(i) > 0:
+                if inspect.isclass(eval(f"fwdpy11.{i}")):
+                    params = params.replace(i, "fwdpy11." + i)
+        params_dict = eval(params)
         return params_dict
 
     params_dict = rebuild_pdict(provenance)

tests/test_tskit_metadata.py

@@ -16,8 +16,9 @@
 # You should have received a copy of the GNU General Public License
 # along with fwdpy11.  If not, see <http://www.gnu.org/licenses/>.
 #
+import copy
+import inspect
 
-import demes
 import fwdpy11
 import pytest
 import tskit
@@ -62,10 +63,12 @@ def test_single_model_params(pop, pdict1):
     ts = pop.dump_tables_to_tskit(model_params=mp)
 
     # reconstruct
+    params = copy.deepcopy(ts.metadata["model_params"])
     for i in dir(fwdpy11):
-        exec(f"from fwdpy11 import {i}")
+        if inspect.isclass(eval(f"fwdpy11.{i}")):
+            params = params.replace(i, "fwdpy11." + i)
 
-    mp_rebuilt = fwdpy11.ModelParams(**eval(ts.metadata["model_params"]))
+    mp_rebuilt = fwdpy11.ModelParams(**eval(params))
 
     assert mp == mp_rebuilt