script to convert roman numerals into ints

Author: webpigeon

scripts/roman.py

@@ -0,0 +1,40 @@
+#! /usr/bin/env python
+##
+# Convert roman numerals into ints
+# Created by Joseph Walton-Rivers
+##
+##
+# Useage: ./roman.py and follow the prompt
+##
+
+roman = {'I':1, 'V':5, 'X':10, 'L':50, 'C':100, 'D':500, 'M':1000}
+roman_input = raw_input("Enter Roman Numeral: ")
+
+def main(roman_input):
+	lowest = 1000
+
+	total = 0
+	skip = []
+	for x in range(0, len(roman_input)):
+		roman_value = roman_input[x]
+		int_value = roman[roman_value]
+
+		# Subtraction rule
+		next_roman_value = roman_input[x+1] if x+1 < len(roman_input) else ''
+		next_int_value = roman[next_roman_value] if next_roman_value != '' else 0	
+		if int_value < next_int_value:
+			int_value = (next_int_value - int_value)
+			skip.append(x+1)
+
+		# Skip the value if it's part of a subsitution rule
+		if x not in skip:
+			total = total + int_value
+
+			# ERROR CHECK: the number should always decrease or be equal to the last
+			if lowest < int_value:
+				print ("ERROR - value goes up!")
+				return 0
+			lowest = int_value
+	return total
+
+print ("the total is "+str(main(roman_input)))