ENH: Allow tuple of Warnings in tm.assert_produces_warning()

Author: kernc

pandas/tests/sparse/frame/test_frame.py

@@ -449,23 +449,26 @@ def test_set_value(self):
 
         # ok, as the index gets converted to object
         frame = self.frame.copy()
-        with tm.assert_produces_warning(FutureWarning,
+        with tm.assert_produces_warning((FutureWarning,
+                                         PerformanceWarning),
                                         check_stacklevel=False):
             res = frame.set_value('foobar', 'B', 1.5)
         assert res.index.dtype == 'object'
 
         res = self.frame
         res.index = res.index.astype(object)
 
-        with tm.assert_produces_warning(FutureWarning,
+        with tm.assert_produces_warning((FutureWarning,
+                                         PerformanceWarning),
                                         check_stacklevel=False):
             res = self.frame.set_value('foobar', 'B', 1.5)
         assert res.index[-1] == 'foobar'
         with tm.assert_produces_warning(FutureWarning,
                                         check_stacklevel=False):
             assert res.get_value('foobar', 'B') == 1.5
 
-        with tm.assert_produces_warning(FutureWarning,
+        with tm.assert_produces_warning((FutureWarning,
+                                         PerformanceWarning),
                                         check_stacklevel=False):
             res2 = res.set_value('foobar', 'qux', 1.5)
         tm.assert_index_equal(res2.columns,

pandas/tests/sparse/series/test_series.py

@@ -477,12 +477,14 @@ def test_get_get_value(self):
     def test_set_value(self):
 
         idx = self.btseries.index[7]
-        with tm.assert_produces_warning(FutureWarning,
+        with tm.assert_produces_warning((FutureWarning,
+                                         PerformanceWarning),
                                         check_stacklevel=False):
             self.btseries.set_value(idx, 0)
         assert self.btseries[idx] == 0
 
-        with tm.assert_produces_warning(FutureWarning,
+        with tm.assert_produces_warning((FutureWarning,
+                                         PerformanceWarning),
                                         check_stacklevel=False):
             self.iseries.set_value('foobar', 0)
         assert self.iseries.index[-1] == 'foobar'

pandas/util/testing.py

@@ -2392,9 +2392,10 @@ def assert_produces_warning(expected_warning=Warning, filter_level="always",
 
     Parameters
     ----------
-    expected_warning : {Warning, False, None}, default Warning
+    expected_warning : {Warning, tuple, False, None}, default Warning
         The type of Exception raised. ``exception.Warning`` is the base
-        class for all warnings. To check that no warning is returned,
+        class for all warnings. To expect mltiple warnings, pass a tuple
+        of warning classes. To check that no warning is returned,
         specify ``False`` or ``None``.
     filter_level : str, default "always"
         Specifies whether warnings are ignored, displayed, or turned
@@ -2441,6 +2442,11 @@ class for all warnings. To check that no warning is returned,
 
     ..warn:: This is *not* thread-safe.
     """
+    # Ensure a tuple
+    if (isinstance(expected_warning, type) and
+        issubclass(expected_warning, Warning)):
+        expected_warning = (expected_warning,)
+
     with warnings.catch_warnings(record=True) as w:
 
         if clear is not None:
@@ -2455,15 +2461,17 @@ class for all warnings. To check that no warning is returned,
                 except Exception:
                     pass
 
-        saw_warning = False
+        saw_warning = set()
         warnings.simplefilter(filter_level)
         yield w
         extra_warnings = []
 
         for actual_warning in w:
             if (expected_warning and issubclass(actual_warning.category,
                                                 expected_warning)):
-                saw_warning = True
+                saw_warning.add(
+                    next(w for w in expected_warning
+                         if issubclass(actual_warning.category, w)))
 
                 if check_stacklevel and issubclass(actual_warning.category,
                                                    (FutureWarning,
@@ -2480,9 +2488,10 @@ class for all warnings. To check that no warning is returned,
             else:
                 extra_warnings.append(actual_warning.category.__name__)
         if expected_warning:
-            msg = "Did not see expected warning of class {name!r}.".format(
-                name=expected_warning.__name__)
-            assert saw_warning, msg
+            unseen = set(expected_warning) - saw_warning
+            msg = ("Did not see expected warning(s) of class: " +
+                   ', '.join(w.__name__ for w in unseen))
+            assert not unseen, msg
         assert not extra_warnings, ("Caused unexpected warning(s): {extra!r}."
                                     ).format(extra=extra_warnings)