Adds display of subseconds when no other units are available in in_words().

Author: sdispater

CHANGELOG.md

@@ -10,6 +10,7 @@
 - Added a `in_timestamp` property to the `Pendulum` class to retrieve the behavior of the now deprecated `timestamp` property.
 - `start_of()`/`end_of()` now supports `hour`, `minute` and `second` units.
 - `astimezone()` now supports timezone strings.
+- `in_words()` now displays subseconds when no other units are available.
 
 ### Changed
 

pendulum/mixins/interval.py

@@ -36,9 +36,19 @@ def in_words(self, locale=None, separator=' ', _periods=None):
             unit, count = period
             if abs(count) > 0:
                 parts.append(
-                    self.translator().transchoice(unit, abs(count), {'count': count}, locale=locale)
+                    self.translator().transchoice(
+                        unit, abs(count), {'count': count}, locale=locale
+                    )
                 )
 
+        if not parts and abs(self.microseconds) > 0:
+            translation = self.translator().transchoice(
+                'second', 1,
+                {'count': '{:.2f}'.format(abs(self.microseconds) / 1e6)},
+                locale=locale
+            )
+            parts.append(translation)
+
         return separator.join(parts)
 
     def __str__(self):

tests/interval_tests/test_in_words.py

@@ -57,3 +57,19 @@ def test_separator(self):
             '168 weeks, 1 day, 2 hours, 1 minute, 25 seconds',
             pi.in_words(separator=', ')
         )
+
+    def test_subseconds(self):
+        pi = Interval(microseconds=123456)
+
+        self.assertEqual(
+            '0.12 second',
+            pi.in_words()
+        )
+
+    def test_subseconds_with_seconds(self):
+        pi = Interval(seconds=12, microseconds=123456)
+
+        self.assertEqual(
+            '12 seconds',
+            pi.in_words()
+        )