ENH: handle datetime.date in Period constructor

Author: Chang She

pandas/tseries/period.py

@@ -1,6 +1,5 @@
 # pylint: disable=E1101,E1103,W0232
-
-from datetime import datetime
+from datetime import datetime, date
 import numpy as np
 
 from pandas.tseries.frequencies import (get_freq_code as _gfc, to_offset,
@@ -104,6 +103,10 @@ def __init__(self, value=None, freq=None, ordinal=None,
             dt = value
             if freq is None:
                 raise ValueError('Must supply freq for datetime value')
+        elif isinstance(value, date):
+            dt = datetime(year=value.year, month=value.month, day=value.day)
+            if freq is None:
+                raise ValueError('Must supply freq for datetime value')
         else:
             msg = "Value must be Period, string, integer, or datetime"
             raise ValueError(msg)

pandas/tseries/tests/test_period.py

@@ -7,7 +7,7 @@
 """
 
 from unittest import TestCase
-from datetime import datetime, timedelta
+from datetime import datetime, date, timedelta
 import unittest
 
 from numpy.ma.testutils import assert_equal
@@ -168,6 +168,14 @@ def test_period_constructor(self):
         i1 = Period(ordinal=200701, freq='M')
         self.assertEqual(i1.year, 18695)
 
+        i1 = Period(datetime(2007, 1, 1), freq='M')
+        i2 = Period('200701', freq='M')
+        self.assertEqual(i1, i2)
+
+        i1 = Period(date(2007, 1, 1), freq='M')
+        i2 = Period(datetime(2007, 1, 1), freq='M')
+        self.assertEqual(i1, i2)
+
         self.assertRaises(ValueError, Period, ordinal=200701)
 
     def test_freq_str(self):