diff --git a/py/hexagram/path.py b/py/hexagram/path.py
index ccf771f..d67bfb0 100644
--- a/py/hexagram/path.py
+++ b/py/hexagram/path.py
@@ -56,12 +56,15 @@ class Path():
     def __init__(self, commands: Iterable):
         self.commands = commands
 
-    def is_command(c):
+    @staticmethod
+    def is_command(c: int):
         return (c >= ord('a') and c <= ord('z')) or (c >= ord('A') and c <= ord('Z'))
 
-    def is_number(c):
+    @staticmethod
+    def is_number(c: int):
         return (c >= ord('0') and c <= ord('9'))
 
+    @staticmethod
     def parse(text: str) -> list:
         commands = list()
         command  = PathCommand()