Added comments in the code to provide a little bit more insight into what's happening.

ptoken.py

@@ -1,4 +1,6 @@
 class Token:
+	# Represents the single smallest unit that makes up an expression.
+	
 	def __init__(self, value, type, is_negative_variable = False):
 		self.value = value
 		self.type = type
@@ -47,19 +49,20 @@ class TokenType:
 
 	@staticmethod
 	def get_operator_verb(token):
+		# Returns the verb that corresponds to the supplied Token object's value field, or
+		# throws an error if the Token object isn't a mathmatical operator.
 		if not token in TokenType.OPERATOR_VERBS:
 			raise ValueError("An operator verb could not be found.", "token")
 		return TokenType.OPERATOR_VERBS[token]
 
 	@staticmethod
 	def get_operator(character):
-		#
-        #Accepts an individual character and returns either the math operator TokenType or unknown.
-        #
+        # Accepts an individual character and returns either the mathmatical operator TokenType or unknown.
 		if not character in TokenType.OPERATORS:
 			return TokenType.unknown
 		return TokenType.OPERATORS[character]
 	
 	@staticmethod
 	def get_token_type_name(tokenType):
+		# Returns the token's full name based on the TokenType value.
 		return TokenType.TOKEN_NAMES[tokenType]