diff -r 6c122e4e1cb2 Lib/datetime.py
--- a/Lib/datetime.py	Sun Feb 14 03:25:48 2016 +0000
+++ b/Lib/datetime.py	Tue Feb 16 16:01:59 2016 +1030
@@ -6,6 +6,7 @@
 
 import time as _time
 import math as _math
+import re
 
 def _cmp(x, y):
     return 0 if x == y else 1 if x > y else -1
@@ -146,6 +147,12 @@
                      "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"]
 _DAYNAMES = [None, "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"]
 
+datetime_re = re.compile(
+    r'(?P<year>\d{4})-(?P<month>\d{2})-(?P<day>\d{2})'
+    r'[T ](?P<hour>\d{2}):(?P<minute>\d{2}):'
+    r'(?P<second>\d{2})(?:(?P<microsecond>\.\d{1,7})\d*)?'
+    r'(?P<tzinfo>Z|[+-]\d{2}:\d{2})?$'
+)
 
 def _build_struct_time(y, m, d, hh, mm, ss, dstflag):
     wday = (_ymd2ord(y, m, d) + 6) % 7
@@ -1386,7 +1393,7 @@
         y, m, d, hh, mm, ss, weekday, jday, dst = converter(t)
         ss = min(ss, 59)    # clamp out leap seconds if the platform has them
         return cls(y, m, d, hh, mm, ss, us, tz)
-
+    
     @classmethod
     def fromtimestamp(cls, t, tz=None):
         """Construct a datetime from a POSIX timestamp (like time.time()).
@@ -1401,6 +1408,37 @@
         return result
 
     @classmethod
+    def fromisoformat(cls, value):
+        """Parses a string and return a datetime.datetime.
+
+        This function supports time zone offsets. When the input contains one,
+        the output uses a timezone with a fixed offset from UTC.
+        Microseconds values after 6 digits are discared.
+
+        Raises ValueError if the input is not well formatted or not a valid datetime.
+        """
+        match = datetime_re.match(value)
+        if not match:
+            raise ValueError('invalid {} iso8601 string : {}'.format(cls.__name__, value))
+        kw = match.groupdict()
+        tzinfo = kw.pop('tzinfo')
+        if tzinfo == 'Z':
+            tzinfo = timezone.utc
+        elif tzinfo is not None:
+            offset_hours, offset_mins = tzinfo[1:].split(':')
+            offset = timedelta(hours=int(offset_hours), minutes=int(offset_mins))
+            if tzinfo[0] == '-':
+                offset = -offset
+            tzinfo = timezone(offset)
+        us = kw.pop('microsecond', None)
+        kw = {k: int(v) for k, v in kw.items() if v is not None}
+        if us:
+            us = round(float(us), 6)
+            kw['microsecond'] = int(us * 1e6)
+        kw['tzinfo'] = tzinfo
+        return cls(**kw)
+
+    @classmethod
     def utcfromtimestamp(cls, t):
         """Construct a naive UTC datetime from a POSIX timestamp."""
         return cls._fromtimestamp(t, True, None)
@@ -2127,6 +2165,7 @@
 # pretty bizarre, and a tzinfo subclass can override fromutc() if it is.
 
 try:
+    raise ImportError
     from _datetime import *
 except ImportError:
     pass
diff -r 6c122e4e1cb2 Lib/test/datetimetester.py
--- a/Lib/test/datetimetester.py	Sun Feb 14 03:25:48 2016 +0000
+++ b/Lib/test/datetimetester.py	Tue Feb 16 16:01:59 2016 +1030
@@ -1847,6 +1847,32 @@
         self.assertEqual(expected.tm_min, got.minute)
         self.assertEqual(expected.tm_sec, got.second)
 
+    def test_fromisoformat(self):
+        # Valid inputs
+        parse_datetime = self.theclass.fromisoformat
+        self.assertEqual(parse_datetime('2012-04-23T09:15:00'),
+            datetime(2012, 4, 23, 9, 15))
+        self.assertEqual(parse_datetime('2012-04-23T09:15:00Z'),
+            datetime(2012, 4, 23, 9, 15, 0, 0, timezone(timedelta(minutes=0))))
+        self.assertEqual(parse_datetime('2012-04-23T10:20:30.400+02:30'),
+            datetime(2012, 4, 23, 10, 20, 30, 400000, timezone(timedelta(hours=2, minutes=30))))
+        self.assertEqual(parse_datetime('2012-04-23T10:20:30.400+02:00'),
+            datetime(2012, 4, 23, 10, 20, 30, 400000, timezone(timedelta(hours=2))))
+        self.assertEqual(parse_datetime('2012-04-23T10:20:30.400-02:00'),
+            datetime(2012, 4, 23, 10, 20, 30, 400000, timezone(timedelta(hours=-2))))
+        # rounding high
+        self.assertEqual(parse_datetime('2012-04-23T10:20:30.4000059'),
+            datetime(2012, 4, 23, 10, 20, 30, 400006))
+        # rounding low + testing long usec decimal we don't care about
+        self.assertEqual(parse_datetime('2012-04-23T10:20:30.400003434'),
+            datetime(2012, 4, 23, 10, 20, 30, 400003))
+        # Invalid inputs
+        with self.assertRaises(ValueError):
+            parse_datetime('20120423091500')
+            parse_datetime('2012-04-56T09:15:90')
+            parse_datetime('2012-05-31T12:14')
+
+
     def test_fromtimestamp(self):
         import time