TST: Use new warnings context manager in all tests

In some places, just remove aparently unnecessary filters.

After this, all cases of ignore filters should be removed from
the tests, making testing (even multiple runs) normally fully
predictable.

2 files changed, 27 insertions, 35 deletions

diff --git a/numpy/lib/tests/test_function_base.py b/numpy/lib/tests/test_function_base.py
index 0d7b11c44..4535c1e7f 100644
--- a/numpy/lib/tests/test_function_base.py
+++ b/numpy/lib/tests/test_function_base.py
@@ -8,7 +8,7 @@ from numpy.testing import (
     run_module_suite, TestCase, assert_, assert_equal, assert_array_equal,
     assert_almost_equal, assert_array_almost_equal, assert_raises,
     assert_allclose, assert_array_max_ulp, assert_warns,
-    assert_raises_regex, dec, clear_and_catch_warnings
+    assert_raises_regex, dec, suppress_warnings
 )
 from numpy.testing.utils import HAS_REFCOUNT
 import numpy.lib.function_base as nfb
@@ -320,7 +320,11 @@ class TestAverage(TestCase):
         a = np.array([[1,2],[3,4]]).view(subclass)
         w = np.array([[1,2],[3,4]]).view(subclass)
 
-        assert_equal(type(np.average(a, weights=w)), subclass)
+        with suppress_warnings() as sup:
+            # Note that the warning is spurious, because the test checks
+            # for weights while a is ignored.
+            sup.filter(FutureWarning, "np.average currently does not preserve")
+            assert_equal(type(np.average(a, weights=w)), subclass)
 
         # also test matrices
         a = np.matrix([[1,2],[3,4]])
@@ -1457,12 +1461,12 @@ class TestHistogram(TestCase):
         a, b = histogram([], bins=([0, 1]))
         assert_array_equal(a, np.array([0]))
         assert_array_equal(b, np.array([0, 1]))
-        
+
     def test_error_binnum_type (self):
         # Tests if right Error is raised if bins argument is float
         vals = np.linspace(0.0, 1.0, num=100)
         histogram(vals, 5)
-        assert_raises(TypeError, histogram, vals, 2.4)   
+        assert_raises(TypeError, histogram, vals, 2.4)
 
     def test_finite_range(self):
         # Normal ranges should be fine
@@ -1792,15 +1796,6 @@ class TestCheckFinite(TestCase):
         assert_(a.dtype == np.float64)
 
 
-class catch_warn_nfb(clear_and_catch_warnings):
-
-    """
-    Context manager to catch, reset warnings in function_base module
-
-    """
-    class_modules = (nfb,)
-
-
 class TestCorrCoef(TestCase):
     A = np.array(
         [[0.15391142, 0.18045767, 0.14197213],
@@ -1837,10 +1832,10 @@ class TestCorrCoef(TestCase):
 
     def test_ddof(self):
         # ddof raises DeprecationWarning
-        with catch_warn_nfb():
+        with suppress_warnings() as sup:
             warnings.simplefilter("always")
             assert_warns(DeprecationWarning, corrcoef, self.A, ddof=-1)
-            warnings.simplefilter("ignore")
+            sup.filter(DeprecationWarning)
             # ddof has no or negligible effect on the function
             assert_almost_equal(corrcoef(self.A, ddof=-1), self.res1)
             assert_almost_equal(corrcoef(self.A, self.B, ddof=-1), self.res2)
@@ -1849,11 +1844,11 @@ class TestCorrCoef(TestCase):
 
     def test_bias(self):
         # bias raises DeprecationWarning
-        with catch_warn_nfb():
+        with suppress_warnings() as sup:
             warnings.simplefilter("always")
             assert_warns(DeprecationWarning, corrcoef, self.A, self.B, 1, 0)
             assert_warns(DeprecationWarning, corrcoef, self.A, bias=0)
-            warnings.simplefilter("ignore")
+            sup.filter(DeprecationWarning)
             # bias has no or negligible effect on the function
             assert_almost_equal(corrcoef(self.A, bias=1), self.res1)
 
@@ -2316,7 +2311,7 @@ class TestInterp(TestCase):
         assert_almost_equal(np.interp(x0, x, y), x0)
         x0 = np.nan
         assert_almost_equal(np.interp(x0, x, y), x0)
-        
+
     def test_complex_interp(self):
         # test complex interpolation
         x = np.linspace(0, 1, 5)
@@ -2335,7 +2330,7 @@ class TestInterp(TestCase):
         x = [-180, -170, -185, 185, -10, -5, 0, 365]
         xp = [190, -190, 350, -350]
         fp = [5+1.0j, 10+2j, 3+3j, 4+4j]
-        y = [7.5+1.5j, 5.+1.0j, 8.75+1.75j, 6.25+1.25j, 3.+3j, 3.25+3.25j, 
+        y = [7.5+1.5j, 5.+1.0j, 8.75+1.75j, 6.25+1.25j, 3.+3j, 3.25+3.25j,
              3.5+3.5j, 3.75+3.75j]
         assert_almost_equal(np.interp(x, xp, fp, period=360), y)
 
diff --git a/numpy/lib/tests/test_io.py b/numpy/lib/tests/test_io.py
index 1474349de..333891d46 100644
--- a/numpy/lib/tests/test_io.py
+++ b/numpy/lib/tests/test_io.py
@@ -19,7 +19,7 @@ from numpy.ma.testutils import assert_equal
 from numpy.testing import (
     TestCase, run_module_suite, assert_warns, assert_,
     assert_raises_regex, assert_raises, assert_allclose,
-    assert_array_equal, temppath, dec, IS_PYPY
+    assert_array_equal, temppath, dec, IS_PYPY, suppress_warnings
 )
 
 
@@ -282,8 +282,8 @@ class TestSavezLoad(RoundtripTest, TestCase):
             # collector, so we catch the warnings.  Because ResourceWarning
             # is unknown in Python < 3.x, we take the easy way out and
             # catch all warnings.
-            with warnings.catch_warnings():
-                warnings.simplefilter("ignore")
+            with suppress_warnings() as sup:
+                sup.filter(Warning)  # TODO: specify exact message
                 for i in range(1, 1025):
                     try:
                         np.load(tmp)["data"]
@@ -687,9 +687,8 @@ class TestLoadTxt(TestCase):
         assert_array_equal(x, a)
 
     def test_empty_file(self):
-        with warnings.catch_warnings():
-            warnings.filterwarnings("ignore",
-                                    message="loadtxt: Empty input file:")
+        with suppress_warnings() as sup:
+            sup.filter(message="loadtxt: Empty input file:")
             c = TextIO()
             x = np.loadtxt(c)
             assert_equal(x.shape, (0,))
@@ -826,9 +825,8 @@ class TestLoadTxt(TestCase):
         assert_(x.shape == (3,))
 
         # Test ndmin kw with empty file.
-        with warnings.catch_warnings():
-            warnings.filterwarnings("ignore",
-                                    message="loadtxt: Empty input file:")
+        with suppress_warnings() as sup:
+            sup.filter(message="loadtxt: Empty input file:")
             f = TextIO()
             assert_(np.loadtxt(f, ndmin=2).shape == (0, 1,))
             assert_(np.loadtxt(f, ndmin=1).shape == (0,))
@@ -974,8 +972,8 @@ class TestFromTxt(TestCase):
         assert_equal(test, ctrl)
 
     def test_skip_footer_with_invalid(self):
-        with warnings.catch_warnings():
-            warnings.filterwarnings("ignore")
+        with suppress_warnings() as sup:
+            sup.filter(ConversionWarning)
             basestr = '1 1\n2 2\n3 3\n4 4\n5  \n6  \n7  \n'
             # Footer too small to get rid of all invalid values
             assert_raises(ValueError, np.genfromtxt,
@@ -1302,9 +1300,8 @@ M   33  21.99
 
     def test_empty_file(self):
         # Test that an empty file raises the proper warning.
-        with warnings.catch_warnings():
-            warnings.filterwarnings("ignore",
-                                    message="genfromtxt: Empty input file:")
+        with suppress_warnings() as sup:
+            sup.filter(message="genfromtxt: Empty input file:")
             data = TextIO()
             test = np.genfromtxt(data)
             assert_equal(test, np.array([]))
@@ -1751,8 +1748,8 @@ M   33  21.99
         assert_raises(ValueError, np.genfromtxt, TextIO(data), max_rows=4)
 
         # Test with invalid not raise
-        with warnings.catch_warnings():
-            warnings.filterwarnings("ignore")
+        with suppress_warnings() as sup:
+            sup.filter(ConversionWarning)
 
             test = np.genfromtxt(TextIO(data), max_rows=4, invalid_raise=False)
             control = np.array([[1., 1.], [2., 2.], [3., 3.], [4., 4.]])