Index: Lib/test/test_datetime.py
===================================================================
--- Lib/test/test_datetime.py	(revision 58132)
+++ Lib/test/test_datetime.py	(working copy)
@@ -868,7 +868,7 @@
         self.assertEqual(format(b, ''), str(dt))
 
         for fmt in ["m:%m d:%d y:%y",
-                    "m:%m d:%d y:%y H:%H M:%M S:%S",
+                    "m:%m d:%d y:%y H:%H M:%M S:%S f:%f",
                     "%z %Z",
                     ]:
             self.assertEqual(format(dt, fmt), dt.strftime(fmt))
@@ -1195,7 +1195,7 @@
         self.assertEqual(format(b, ''), str(dt))
 
         for fmt in ["m:%m d:%d y:%y",
-                    "m:%m d:%d y:%y H:%H M:%M S:%S",
+                    "m:%m d:%d y:%y H:%H M:%M S:%S f:%f",
                     "%z %Z",
                     ]:
             self.assertEqual(format(dt, fmt), dt.strftime(fmt))
@@ -1556,9 +1556,9 @@
 
     def test_more_strftime(self):
         # This tests fields beyond those tested by the TestDate.test_strftime.
-        t = self.theclass(2004, 12, 31, 6, 22, 33)
-        self.assertEqual(t.strftime("%m %d %y %S %M %H %j"),
-                                    "12 31 04 33 22 06 366")
+        t = self.theclass(2004, 12, 31, 6, 22, 33, 47)
+        self.assertEqual(t.strftime("%m %d %y %S %M %H %j %f"),
+                                    "12 31 04 33 22 06 366 000047")
 
     def test_extract(self):
         dt = self.theclass(2002, 3, 4, 18, 45, 3, 1234)
@@ -1831,7 +1831,7 @@
 
     def test_strftime(self):
         t = self.theclass(1, 2, 3, 4)
-        self.assertEqual(t.strftime('%H %M %S'), "01 02 03")
+        self.assertEqual(t.strftime('%H %M %S %f'), "01 02 03 000004")
         # A naive object replaces %z and %Z with empty strings.
         self.assertEqual(t.strftime("'%z' '%Z'"), "'' ''")
 
Index: Modules/datetimemodule.c
===================================================================
--- Modules/datetimemodule.c	(revision 58132)
+++ Modules/datetimemodule.c	(working copy)
@@ -1177,10 +1177,24 @@
 	return NULL;
 }
 
+static PyObject *
+make_freplacement(PyObject *object)
+{
+	char freplacement[7];
+	if (PyTime_Check(object))
+	    sprintf(freplacement, "%06d", TIME_GET_MICROSECOND(object));
+	else if (PyDateTime_Check(object))
+	    sprintf(freplacement, "%06d", DATE_GET_MICROSECOND(object));
+	else
+	    sprintf(freplacement, "%06d", 0);
+
+	return PyBytes_FromStringAndSize(freplacement, strlen(freplacement));
+}
+
 /* I sure don't want to reproduce the strftime code from the time module,
  * so this imports the module and calls it.  All the hair is due to
- * giving special meanings to the %z and %Z format codes via a preprocessing
- * step on the format string.
+ * giving special meanings to the %z, %Z and %f format codes via a
+ * preprocessing step on the format string.
  * tzinfoarg is the argument to pass to the object's tzinfo method, if
  * needed.
  */
@@ -1192,6 +1206,7 @@
 
 	PyObject *zreplacement = NULL;	/* py string, replacement for %z */
 	PyObject *Zreplacement = NULL;	/* py string, replacement for %Z */
+	PyObject *freplacement = NULL;	/* py string, replacement for %f */
 
 	const char *pin;/* pointer to next char in input format */
         Py_ssize_t flen;/* length of input format */
@@ -1239,11 +1254,11 @@
 		}
 	}
 
-	/* Scan the input format, looking for %z and %Z escapes, building
+	/* Scan the input format, looking for %z/%Z/%f escapes, building
 	 * a new format.  Since computing the replacements for those codes
 	 * is expensive, don't unless they're actually used.
 	 */
-	totalnew = flen + 1;	/* realistic if no %z/%Z */
+	totalnew = flen + 1;	/* realistic if no %z/%Z/%f */
 	newfmt = PyBytes_FromStringAndSize(NULL, totalnew);
 	if (newfmt == NULL) goto Done;
 	pnew = PyBytes_AsString(newfmt);
@@ -1301,6 +1316,18 @@
 			ptoappend = PyBytes_AS_STRING(Zreplacement);
 			ntoappend = PyBytes_GET_SIZE(Zreplacement);
 		}
+		else if (ch == 'f') {
+			/* format microseconds */
+			if (freplacement == NULL) {
+				freplacement = make_freplacement(object);
+				if (freplacement == NULL)
+					goto Done;
+			}
+			assert(freplacement != NULL);
+			assert(PyBytes_Check(freplacement));
+			ptoappend = PyBytes_AS_STRING(freplacement);
+			ntoappend = PyBytes_GET_SIZE(freplacement);
+		}
 		else {
 			/* percent followed by neither z nor Z */
 			ptoappend = pin - 2;
@@ -1347,6 +1374,7 @@
 		Py_DECREF(time);
     	}
  Done:
+	Py_XDECREF(freplacement);
 	Py_XDECREF(zreplacement);
 	Py_XDECREF(Zreplacement);
 	Py_XDECREF(newfmt);
@@ -3159,7 +3187,7 @@
 {
 	char buf[100];
 	PyObject *result;
-	int us = TIME_GET_MICROSECOND(self);;
+	int us = TIME_GET_MICROSECOND(self);
 
 	if (us)
 		result = PyUnicode_FromFormat("%02d:%02d:%02d.%06d",
Index: Doc/library/datetime.rst
===================================================================
--- Doc/library/datetime.rst	(revision 58132)
+++ Doc/library/datetime.rst	(working copy)
@@ -1294,10 +1294,16 @@
 be used, as time objects have no such values.  If they're used anyway, ``1900``
 is substituted for the year, and ``0`` for the month and day.
 
-For :class:`date` objects, the format codes for hours, minutes, and seconds
-should not be used, as :class:`date` objects have no such values.  If they're
-used anyway, ``0`` is substituted for them.
+For :class:`date` objects, the format codes for hours, minutes, seconds, and
+fractions of sections should not be used, as :class:`date` objects have no
+such values.  If they're used anyway, ``0`` is substituted for them.
 
+:class:`time` and :class:`datetime` objects support a ``%f`` format code
+which expands to the number of microseconds in the object, zero-padded on
+the left to six places.
+
+.. versionadded:: 2.6
+
 For a naive object, the ``%z`` and ``%Z`` format codes are replaced by empty
 strings.