BUG: 10720 adding all

slight update

Author: springcoil

pandas/core/common.py

@@ -1718,7 +1718,8 @@ def _interpolate_scipy_wrapper(x, y, new_x, method, fill_value=None,
                                     bounds_error=bounds_error)
         new_y = terp(new_x)
     elif method == 'spline':
-        # GH #10633
+        
+        # GH 10633
         if not order:
             raise ValueError("order needs to be specified and greater than 0")
         terp = interpolate.UnivariateSpline(x, y, k=order, **kwargs)

pandas/tests/test_generic.py

@@ -799,6 +799,14 @@ def test_nan_interpolate(self):
         tm._skip_if_no_scipy()
         result = s.interpolate(method='polynomial', order=1)
         assert_series_equal(result, expected)
+    # GH #10633: first attempt
+    def test_interpolate_spline(self):
+        np.random.seed(1)
+        s = pd.Series(np.arange(10)**2)
+        s[np.random.randint(0,9,3)] = np.nan
+        with tm.assertRaises(ValueError):
+            s.interpolate(method='spline')
+        
 
     def test_nan_irregular_index(self):
         s = Series([1, 2, np.nan, 4], index=[1, 3, 5, 9])

pandas/tseries/tests/test_timeseries.py

@@ -923,8 +923,8 @@ def test_to_datetime_with_apply(self):
         assert_series_equal(result, expected)
 
         td = pd.Series(['May 04', 'Jun 02', ''], index=[1,2,3])
-        self.assertRaises(ValueError, lambda : pd.to_datetime(td,format='%b %y', errors='raise'))
-        self.assertRaises(ValueError, lambda : td.apply(pd.to_datetime, format='%b %y', errors='raise'))
+        self.assertRaises(ValueError, 'Unknown string format. You can coerce errors to NaT by passing coerce', lambda : pd.to_datetime(td,format='%b %y', errors='raise'))
+        self.assertRaises(ValueError, 'Unknown string format. You can coerce errors to NaT by passing coerce',lambda : td.apply(pd.to_datetime, format='%b %y', errors='raise'))
         expected = pd.to_datetime(td, format='%b %y', errors='coerce')
 
         result = td.apply(lambda x: pd.to_datetime(x, format='%b %y', errors='coerce'))