Some syntaxis fixes (applied pep8).

src/node.py

@@ -90,7 +90,7 @@ TOKEN_MAP = {
         OP_HINT: 'HINT',
         OP_REWRITE_ALL: 'REWRITE_ALL',
         OP_REWRITE: 'REWRITE',
-}
+        }
 
 
 def to_expression(obj):

src/parser.py

@@ -51,8 +51,8 @@ class Parser(BisonParser):
     # ----------------------------------------------------------------
     # TODO: add a runtime check to verify that this token list match the list
     # of tokens of the lex script.
-    tokens =  ['NUMBER', 'IDENTIFIER', 'NEWLINE', 'QUIT', 'RAISE', 'GRAPH', \
-               'LPAREN', 'RPAREN'] + TOKEN_MAP.values()
+    tokens = ['NUMBER', 'IDENTIFIER', 'NEWLINE', 'QUIT', 'RAISE', 'GRAPH', \
+              'LPAREN', 'RPAREN'] + TOKEN_MAP.values()
 
     # ------------------------------
     # precedences

src/rules/numerics.py

@@ -219,7 +219,6 @@ def multiply_numerics(root, args):
     """
     scope, c0, c1 = args
 
-
     # Replace the left node with the new expression
     substitution = Leaf(c0.value * c1.value).negate(c0.negated + c1.negated)
     scope.replace(c0, substitution)