Add two isoformat() methods. One for Date and one for Interval.

This permits the dicttoxml library to print these data types.
The dicttoxml library is optional and can be used by the rest
interface to support xml output.

Author: rouilj

roundup/date.py

@@ -615,6 +615,16 @@ def formal(self, sep='.', sec='%02d'):
         return f%(self.year, self.month, self.day, self.hour, self.minute,
             self.second)
 
+    def isoformat(self):
+        ''' Represent the date/time in isoformat standard
+
+            Originally needed for xml output support using
+            dicttoxml in the rest interface.
+        '''
+        f = '%%04d-%%02d-%%02d%s%%02d:%%02d:%s'%("T", "%02.6d")
+        return f%(self.year, self.month, self.day, self.hour, self.minute,
+            self.second)
+
     def pretty(self, format='%d %B %Y'):
         ''' print up the date date using a pretty format...
 
@@ -1075,6 +1085,15 @@ def serialise(self):
         return '%s%04d%02d%02d%02d%02d%02d'%(sign, self.year, self.month,
             self.day, self.hour, self.minute, self.second)
 
+    def isoformat(self):
+        '''Represent interval as an ISO 8061 duration (absolute value)
+        
+           Originally needed for xml output support using
+           dicttoxml in the rest interface.
+        '''
+        return 'P%04dY%02dM%02dDT%02dH%02dM%02dS'%(self.year, self.month,
+            self.day, self.hour, self.minute, self.second)
+
     def as_seconds(self):
         '''Calculate the Interval as a number of seconds.