ENH: add is_full method to PeriodIndex close #1114

Author: wesm

pandas/tseries/period.py

@@ -656,6 +656,19 @@ def __iter__(self):
     def is_all_dates(self):
         return True
 
+    @property
+    def is_full(self):
+        """
+        Returns True if there are any missing periods from start to end
+        """
+        if len(self) == 0:
+            return True
+        if not self.is_monotonic:
+            raise ValueError('Index is not monotonic')
+        values = self.values
+        return ((values[1:] - values[:-1]) < 2).all()
+
+
     @property
     def freqstr(self):
         return self.freq

pandas/tseries/tests/test_period.py

@@ -1464,6 +1464,23 @@ def _check_field(self, periodindex, fieldname):
         for x, val in zip(periodindex, field_idx):
             assert_equal(getattr(x, fieldname), val)
 
+    def test_is_full(self):
+        index = PeriodIndex([2005, 2007, 2009], freq='A')
+        self.assert_(not index.is_full)
+
+        index = PeriodIndex([2005, 2006, 2007], freq='A')
+        self.assert_(index.is_full)
+
+        index = PeriodIndex([2005, 2005, 2007], freq='A')
+        self.assert_(not index.is_full)
+
+        index = PeriodIndex([2005, 2005, 2006], freq='A')
+        self.assert_(index.is_full)
+
+        index = PeriodIndex([2006, 2005, 2005], freq='A')
+        self.assertRaises(ValueError, getattr, index, 'is_full')
+
+        self.assert_(index[:0].is_full)
 
 def _permute(obj):
     return obj.take(np.random.permutation(len(obj)))