Fixed bug when evaluating numbers several times

src/parsers/PythonParser.py

@@ -40,10 +40,12 @@ class PythonNode(Node):
         self.ast_ = ast_  # if ast_ else ast.parse(source, mode="eval") if source else None
         self.objects = objects or {}  # when objects (mainly concepts or rules) are recognized in the expression
         self.compiled = None
+        self.ast_str = self.get_dump(self.ast_)
 
     def init_ast(self):
         if self.ast_ is None and self.source:
             self.ast_ = ast.parse(self.source, mode="eval")
+            self.ast_str = self.get_dump(self.ast_)
         return self
 
     def get_compiled(self):
@@ -77,6 +79,8 @@ class PythonNode(Node):
 
     @staticmethod
     def get_dump(ast_):
+        if not ast_:
+            return None
         dump = ast.dump(ast_)
         for to_remove in [", ctx=Load()", ", kind=None", ", type_ignores=[]"]:
             dump = dump.replace(to_remove, "")