Our submission

romans.py

@@ -0,0 +1,56 @@
+class Romans:
+
+    roman_from_num = {
+        1: "I",
+        5: "V",
+        10: "X",
+        50: "L",
+        100: "C",
+        500: "D",
+        1000: "M"
+    }
+
+    num_from_roman = {
+        "I": 1,
+        "V": 5,
+        "X": 10,
+        "L": 50,
+        "C": 100,
+        "D": 500,
+        "M": 1000
+    }
+
+    def __init__(self, value):
+        if type(value) == str:
+            self._str = value
+            self._num = Romans.str_to_num(value)
+        elif type(value) == int:
+            self._str = Romans.num_to_str(value)
+            self._num = value
+
+    def __str__(self):
+        return self._str
+
+    def __int__(self):
+        return self._num
+
+    @staticmethod
+    def str_to_num(value):
+        result = [num_from_roman.get(i) for i in value]
+
+        for i in range(len(result)):
+            if result[i] < result[min(len(result)-1, i+1)]:
+                result[i] *= -1
+
+        return sum(result)
+
+    @staticmethod
+    def num_to_str(value):
+        result = ""
+        for v in sorted(num_from_roman.keys(), reverse=True):
+            unit_count = value // v
+            result += num_from_roman[v] * unit_count
+            value -= unit_count* v
+
+        result = result.replace("VIIII", "IX").replace("LXXXX", "XC").replace("DCCCC", "CM")
+        return result.replace("IIII", "IV").replace("XXXX", "XL").replace("CCCC", "CD")

romans.test.py

@@ -0,0 +1,64 @@
+import unittest
+from romans import Romans as R
+
+class TestRomans(unittest.TestCase):
+
+    def test_i(self):
+        self.assertEqual(1, int(R("I")))
+
+    def test_v(self):
+        self.assertEqual(5, int(R("V")))
+
+    def test_x(self):
+        self.assertEqual(10, int(R("X")))
+
+    def test_l(self):
+        self.assertEqual(50, int(R("L")))
+
+    def test_c(self):
+        self.assertEqual(100, int(R("C")))
+
+    def test_d(self):
+        self.assertEqual(500, int(R("D")))
+
+    def test_m(self):
+        self.assertEqual(1000, int(R("M")))
+
+    def test_ii(self):
+        self.assertEqual(2, int(R("II")))
+
+    def test_iv(self):
+        self.assertEqual(4, int(R("IV")))
+
+    def test_xlix(self):
+        self.assertEqual(49, int(R("XLIX")))
+
+    def test_mmm(self):
+        self.assertEqual(3000, int(R("MMM")))
+
+    def test_1(self):
+        self.assertEqual("I", str(R(1)))
+
+    def test_2(self):
+        self.assertEqual("II", str(R(2)))
+
+    def test_3000(self):
+        self.assertEqual("MMM", str(R(3000)))
+
+    def test_9(self):
+        self.assertEqual("IX", str(R(9)))
+
+    def test_49(self):
+        self.assertEqual("XLIX", str(R(49)))
+
+    def test_400(self):
+        self.assertEqual("CD", str(R(400)))
+
+    def test_900(self):
+        self.assertEqual("CM", str(R(900)))
+
+    def test_999(self):
+        self.assertEqual("CMXCIX", str(R(999)))
+
+if __name__ == '__main__':
+    unittest.main()