add to_ordinal method

num2words/lang_SW.py

@@ -113,20 +113,32 @@ def thousands_to_cardinal(self, number):
                 return f'{ONES[thousands]} elfu na {self.tens_to_cardinal(remainder)}'
             elif thousands < 100:
                 # thousands = 10 - 99
-                return f'{self.tens_to_cardinal(thousands)} elfu na {self.tens_to_cardinal(remainder)}'
+                return (
+                    f'{self.tens_to_cardinal(thousands)} elfu na '
+                    f'{self.tens_to_cardinal(remainder)}'
+                )
             elif thousands < 1000:
                 # thousands = 100 - 999
-                return f'{self.hundreds_to_cardinal(thousands)} elfu, {self.tens_to_cardinal(remainder)}'
+                return (
+                    f'{self.hundreds_to_cardinal(thousands)} elfu, '
+                    f'{self.tens_to_cardinal(remainder)}'
+                )
         elif remainder < 1000:
             if thousands < 10:
                 # thousands = 1 - 9
                 return f'{ONES[thousands]} elfu, {self.hundreds_to_cardinal(remainder)}'
             elif thousands < 100:
                 # thousands = 10 - 99
-                return f'{self.tens_to_cardinal(thousands)} elfu, {self.hundreds_to_cardinal(remainder)}'
+                return (
+                    f'{self.tens_to_cardinal(thousands)} elfu, '
+                    f'{self.hundreds_to_cardinal(remainder)}'
+                )
             else:
                 # thousands = 100 - 999
-                return f'{self.hundreds_to_cardinal(thousands)} elfu, {self.hundreds_to_cardinal(remainder)}'
+                return (
+                    f'{self.hundreds_to_cardinal(thousands)} elfu, '
+                    f'{self.hundreds_to_cardinal(remainder)}'
+                )
 
     def big_number_to_cardinal(self, number):
         digits = [c for c in str(number)]
@@ -180,3 +192,13 @@ def to_cardinal(self, number):
             # 1_000_000 - Infinity
             string = self.big_number_to_cardinal(int(number))
         return string
+
+    def to_ordinal(self, number):
+        '''Converts number to ordinal.'''
+        if number <= 0:
+            raise Exception('number must be greater than zero to convert to ordinal')
+        if number == 1:
+            return 'kwanza'
+        if number == 2:
+            return 'pili'
+        return self.to_cardinal(number)

tests/test_sw.py

@@ -111,13 +111,26 @@ def test_big_numbers(self):
         )
         self.assertEqual(
             num2words(911_581_317, lang='sw'),
-            'mia tisa kumi na moja milioni, mia tano themanini na moja elfu, mia tatu kumi na saba',
+            'mia tisa kumi na moja milioni, mia tano themanini na moja elfu, '
+            'mia tatu kumi na saba',
         )
         self.assertEqual(
             num2words(1_911_581_317, lang='sw'),
-            'moja bilioni, mia tisa kumi na moja milioni, mia tano themanini na moja elfu, mia tatu kumi na saba',
+            'moja bilioni, mia tisa kumi na moja milioni, mia tano themanini '
+            'na moja elfu, mia tatu kumi na saba',
         )
         self.assertEqual(
             num2words(882_911_581_317, lang='sw'),
-            'mia nane themanini na mbili bilioni, mia tisa kumi na moja milioni, mia tano themanini na moja elfu, mia tatu kumi na saba',
+            'mia nane themanini na mbili bilioni, mia tisa kumi na moja '
+            'milioni, mia tano themanini na moja elfu, mia tatu kumi na saba',
+        )
+
+    def test_number_to_ordinal(self):
+        self.assertEqual(num2words(1, ordinal=True, lang='sw'), 'kwanza')
+        self.assertEqual(num2words(2, ordinal=True, lang='sw'), 'pili')
+        self.assertEqual(num2words(3, ordinal=True, lang='sw'), 'tatu')
+        self.assertEqual(num2words(9, ordinal=True, lang='sw'), 'tisa')
+        self.assertEqual(num2words(12, ordinal=True, lang='sw'), 'kumi na mbili')
+        self.assertRaises(
+            Exception, 'number must be greater than zero to convert to ordinal'
         )