TST: suppress warnings we cant do anything about (#37522)

Author: jbrockmendel

pandas/tests/io/excel/test_readers.py

@@ -21,7 +21,6 @@
         "xlrd",
         marks=[
             td.skip_if_no("xlrd"),
-            pytest.mark.filterwarnings("ignore:.*(tree\\.iter|html argument)"),
         ],
     ),
     pytest.param(
@@ -35,7 +34,6 @@
         None,
         marks=[
             td.skip_if_no("xlrd"),
-            pytest.mark.filterwarnings("ignore:.*(tree\\.iter|html argument)"),
         ],
     ),
     pytest.param("pyxlsb", marks=td.skip_if_no("pyxlsb")),

pandas/tests/io/pytables/__init__.py

@@ -0,0 +1,9 @@
+import pytest
+
+pytestmark = [
+    # pytables https://github.com/PyTables/PyTables/issues/822
+    pytest.mark.filterwarnings(
+        "ignore:a closed node found in the registry:UserWarning"
+    ),
+    pytest.mark.filterwarnings(r"ignore:tostring\(\) is deprecated:DeprecationWarning"),
+]

pandas/util/_test_decorators.py

@@ -27,6 +27,7 @@ def test_foo():
 from distutils.version import LooseVersion
 import locale
 from typing import Callable, Optional
+import warnings
 
 import numpy as np
 import pytest
@@ -51,10 +52,20 @@ def safe_import(mod_name: str, min_version: Optional[str] = None):
     object
         The imported module if successful, or False
     """
-    try:
-        mod = __import__(mod_name)
-    except ImportError:
-        return False
+    with warnings.catch_warnings():
+        # Suppress warnings that we can't do anything about,
+        #  e.g. from aiohttp
+        warnings.filterwarnings(
+            "ignore",
+            category=DeprecationWarning,
+            module="aiohttp",
+            message=".*decorator is deprecated since Python 3.8.*",
+        )
+
+        try:
+            mod = __import__(mod_name)
+        except ImportError:
+            return False
 
     if not min_version:
         return mod