do not use yacc.yacc() outputdir option as this causes tables to always be regenerated

.gitignore

@@ -1 +1,2 @@
 parser.out
+parsetab.py

parser/.gitignore

@@ -1 +0,0 @@
-parsetab.py

parser/Parser.py

@@ -9,7 +9,7 @@ class Parser(object):
         self.input = input
         self.lexer = Lexer()
         self.tokens = self.lexer.tokens
-        self.parser = yacc.yacc(module = self, outputdir = 'parser')
+        self.parser = yacc.yacc(module = self)
         self.saw_error = False
 
     def p_unit(self, p):