Merge pull request #468 from bashtage/check-start-end-date

BUG: Verify start <= end

Author: bashtage

pandas_datareader/_utils.py

@@ -34,6 +34,8 @@ def _sanitize_dates(start, end):
         start = dt.datetime(2010, 1, 1)
     if end is None:
         end = dt.datetime.today()
+    if start > end:
+        raise ValueError('start must be an earlier date than end')
     return start, end
 
 

pandas_datareader/tests/test_bankofcanada.py

@@ -16,8 +16,8 @@ def get_symbol(currency_code, inverted=False):
             return 'FX{}CAD'.format(currency_code)
 
     def check_bankofcanada_count(self, code):
-        df = web.DataReader(self.get_symbol(code), 'bankofcanada',
-                            date.today() - timedelta(days=30), date.today())
+        start, end = date.today() - timedelta(days=30), date.today()
+        df = web.DataReader(self.get_symbol(code), 'bankofcanada', start, end)
         assert df.size > 15
 
     def check_bankofcanada_valid(self, code):
@@ -57,7 +57,7 @@ def test_bankofcanada_eur_inverted(self):
         self.check_bankofcanada_inverted('EUR')
 
     def test_bankofcanada_bad_range(self):
-        with pytest.raises(RemoteDataError):
+        with pytest.raises(ValueError):
             web.DataReader('FXCADUSD', 'bankofcanada',
                            date.today(), date.today() - timedelta(days=30))