Add humanize_remaining formatter (#671)

* Add humanize_remaining formatter

Allows for formating the time remaning to next event in _human readable
format_. Work only if `humanize` module is available.

i3pystatus/calendar/__init__.py

@@ -8,6 +8,11 @@ from i3pystatus import IntervalModule, formatp, SettingsBase
 from i3pystatus.core.color import ColorRangeModule
 from i3pystatus.core.desktop import DesktopNotification
 
+try:
+    import humanize
+except ImportError:
+    pass
+
 
 def strip_microseconds(delta):
     return delta - timedelta(microseconds=delta.microseconds)
@@ -50,7 +55,8 @@ class CalendarEvent:
         """
         event_dict = dict(
             title=self.title,
-            remaining=self.time_remaining
+            remaining=self.time_remaining,
+            humanize_remaining=self.humanize_time_remaining,
         )
 
         def is_formatter(x):
@@ -64,6 +70,13 @@ class CalendarEvent:
     def time_remaining(self):
         return strip_microseconds(self.start - datetime.now(tz=self.start.tzinfo))
 
+    @property
+    def humanize_time_remaining(self):
+        try:
+            return humanize.naturaltime(datetime.now(tz=self.start.tzinfo) - self.start)
+        except NameError:
+            raise ImportError('Missing humanize module')
+
     def __str__(self):
         return "{}(title='{}', start={}, end={}, recurring={})" \
             .format(type(self).__name__,
@@ -112,8 +125,11 @@ class Calendar(IntervalModule, ColorRangeModule):
 
     * {title} - the title or summary of the event
     * {remaining_time} - how long until this event is due
+    * {humanize_remaining} - how long until this event is due in human readable format
 
     Additional formatters may be provided by the backend, consult their documentation for details.
+
+    .. note:: Optionally requires `humanize` to display time in human readable format.
     """
 
     settings = (