Add PGF.writeToFile. Add categoryProbability, but it seems pgf_category_prob always returns 0.

src/runtime/python/tests/test_basic.py

@@ -77,6 +77,12 @@ def test_newNGF_existing(NGF):
     with pytest.raises(FileExistsError):
         newNGF("empty", "./basic.ngf")
 
+# writePGF
+
+def test_writePGF(PGF):
+    PGF.writeToFile("./copy.pgf")
+    os.remove("./copy.pgf") # cleanup
+
 # abstract syntax
 
 def test_abstractName(PGF):

src/runtime/python/tests/test_transactions.py

@@ -70,6 +70,11 @@ def test_original_function_prob(gr1):
     #     gr1.functionProbability("foo")
     assert gr1.functionProbability("foo") == float('inf')
 
+def test_original_category_prob(gr1):
+    # with pytest.raises(KeyError):
+    #     gr1.categoryProbability("Q")
+    assert gr1.categoryProbability("Q") == float('inf')
+
 # gr2
 
 def test_extended_functions(gr2):
@@ -89,6 +94,9 @@ def test_extended_function_prob(gr2):
     # assert gr2.functionProbability("foo") == prob
     assert math.isclose(gr2.functionProbability("foo"), prob, rel_tol=1e-06)
 
+def test_extended_category_prob(gr2):
+    assert gr2.categoryProbability("Q") == prob
+
 # gr3
 
 def test_branched_functions(gr3):