fix interpolation related issue with scipy 0.19

Author: zym1010

pandas/tests/frame/test_missing.py

@@ -548,7 +548,7 @@ def test_interp_nan_idx(self):
             df.interpolate(method='values')
 
     def test_interp_various(self):
-        tm.skip_if_no_package('scipy', max_version='0.19.0')
+        tm._skip_if_no_scipy()
 
         df = DataFrame({'A': [1, 2, np.nan, 4, 5, np.nan, 7],
                         'C': [1, 2, 3, 5, 8, 13, 21]})
@@ -561,8 +561,13 @@ def test_interp_various(self):
         assert_frame_equal(result, expected)
 
         result = df.interpolate(method='cubic')
-        expected.A.loc[3] = 2.81621174
-        expected.A.loc[13] = 5.64146581
+        import scipy
+        if scipy.__version__ >= LooseVersion('0.19.0'):
+            expected.A.loc[3] = 2.81547781
+            expected.A.loc[13] = 5.52964175
+        else:
+            expected.A.loc[3] = 2.81621174
+            expected.A.loc[13] = 5.64146581
         assert_frame_equal(result, expected)
 
         result = df.interpolate(method='nearest')
@@ -571,8 +576,12 @@ def test_interp_various(self):
         assert_frame_equal(result, expected, check_dtype=False)
 
         result = df.interpolate(method='quadratic')
-        expected.A.loc[3] = 2.82533638
-        expected.A.loc[13] = 6.02817974
+        if scipy.__version__ >= LooseVersion('0.19.0'):
+            expected.A.loc[3] = 2.82150771
+            expected.A.loc[13] = 6.12648668
+        else:
+            expected.A.loc[3] = 2.82533638
+            expected.A.loc[13] = 6.02817974
         assert_frame_equal(result, expected)
 
         result = df.interpolate(method='slinear')
@@ -585,10 +594,6 @@ def test_interp_various(self):
         expected.A.loc[13] = 5
         assert_frame_equal(result, expected, check_dtype=False)
 
-        result = df.interpolate(method='quadratic')
-        expected.A.loc[3] = 2.82533638
-        expected.A.loc[13] = 6.02817974
-        assert_frame_equal(result, expected)
 
     def test_interp_alt_scipy(self):
         tm._skip_if_no_scipy()

pandas/tests/series/test_missing.py

@@ -4,6 +4,7 @@
 import pytz
 from datetime import timedelta, datetime
 
+from distutils.version import LooseVersion
 from numpy import nan
 import numpy as np
 import pandas as pd
@@ -827,7 +828,7 @@ def test_interp_quad(self):
         assert_series_equal(result, expected)
 
     def test_interp_scipy_basic(self):
-        tm.skip_if_no_package('scipy', max_version='0.19.0')
+        tm._skip_if_no_scipy()
 
         s = Series([1, 3, np.nan, 12, np.nan, 25])
         # slinear
@@ -852,7 +853,11 @@ def test_interp_scipy_basic(self):
         result = s.interpolate(method='zero', downcast='infer')
         assert_series_equal(result, expected)
         # quadratic
-        expected = Series([1, 3., 6.769231, 12., 18.230769, 25.])
+        import scipy
+        if scipy.__version__ >= LooseVersion('0.19.0'):
+            expected = Series([1, 3., 6.823529, 12., 18.058824, 25.])
+        else:
+            expected = Series([1, 3., 6.769231, 12., 18.230769, 25.])
         result = s.interpolate(method='quadratic')
         assert_series_equal(result, expected)