Merge pull request #7712 from cpcloud/period-index-constructor

BUG: PeriodIndex constructor doesn't work with Series objects

Author: cpcloud

doc/source/v0.14.1.txt

@@ -291,4 +291,4 @@ Bug Fixes
 
 - Bug in ``to_sql`` taking the boolean column as text column (:issue:`7678`)
 - Bug in grouped `hist` doesn't handle `rot` kw and `sharex` kw properly (:issue:`7234`)
-
+- Bug (regression) in ``PeriodIndex`` constructor when passed ``Series`` objects (:issue:`7701`).

pandas/tseries/period.py

@@ -14,7 +14,7 @@
 
 import pandas.core.common as com
 from pandas.core.common import (isnull, _INT64_DTYPE, _maybe_box,
-                                _values_from_object)
+                                _values_from_object, ABCSeries)
 from pandas import compat
 from pandas.lib import Timestamp
 import pandas.lib as lib
@@ -1261,13 +1261,13 @@ def _range_from_fields(year=None, month=None, quarter=None, day=None,
 def _make_field_arrays(*fields):
     length = None
     for x in fields:
-        if isinstance(x, (list, np.ndarray)):
+        if isinstance(x, (list, np.ndarray, ABCSeries)):
             if length is not None and len(x) != length:
                 raise ValueError('Mismatched Period array lengths')
             elif length is None:
                 length = len(x)
 
-    arrays = [np.asarray(x) if isinstance(x, (np.ndarray, list))
+    arrays = [np.asarray(x) if isinstance(x, (np.ndarray, list, ABCSeries))
               else np.repeat(x, length) for x in fields]
 
     return arrays

pandas/tseries/tests/test_period.py

@@ -1281,6 +1281,15 @@ def test_constructor_nat(self):
         self.assertRaises(
             ValueError, period_range, start='2011-01-01', end='NaT', freq='M')
 
+    def test_constructor_year_and_quarter(self):
+        year = pd.Series([2001, 2002, 2003])
+        quarter = year - 2000
+        idx = PeriodIndex(year=year, quarter=quarter)
+        strs = ['%dQ%d' % t for t in zip(quarter, year)]
+        lops = list(map(Period, strs))
+        p = PeriodIndex(lops)
+        tm.assert_index_equal(p, idx)
+
     def test_is_(self):
         create_index = lambda: PeriodIndex(freq='A', start='1/1/2001',
                                            end='12/1/2009')