Added test for stringification

tests/test_parsing.py

@@ -242,6 +242,33 @@ def test_index_assignment(string, val1, d):
     print (repr(nml), d)
     assert nml["val"] == d
 
+
+@pytest.mark.parametrize("string", ["&nml {} /", "&nml {} val2=34 /"])
+@pytest.mark.parametrize("val1", ["lala", "((1 + 2) + 3)", 3, 3.0, 3e6, ".T."])
+@pytest.mark.parametrize("d", [{1: None, 2: 35},{1: None}])
+def test_index_assignment_to_str(string, d, val1):
+    val_str = ""
+    try:
+        int(eval(val1))
+        is_expression = True
+    except:
+        is_expression = False
+    is_bool = (val1 == ".T.")
+    d[1] = val1
+    for k, v in d.items():
+        if is_expression | is_bool:
+            val_str += "val({}) = {} ".format(k, v)
+        else:
+            val_str += "val({}) = {} ".format(k, repr(v))
+    if is_expression:
+        d[1] = eval(d[1])
+    if is_bool:
+        d[1] = (val1 == ".T.")
+    nml_string = string.format(val_str)
+    nml = namelist.parse_namelist_string(nml_string)["nml"]
+    assert nml_string == str(nml)
+
+
 @pytest.mark.parametrize("string", ["&nml val= {}, val2='lsl'/"])
 @pytest.mark.parametrize("op", ["+", "-", "/", "*", "**"])
 @pytest.mark.parametrize(