Add log.ignore_py_warnings()

qutebrowser/utils/log.py

@@ -167,9 +167,14 @@ def init_log(args):
         root.addHandler(ram)
     root.setLevel(logging.NOTSET)
     logging.captureWarnings(True)
+    _init_py_warnings()
+    QtCore.qInstallMessageHandler(qt_message_handler)
+
+
+def _init_py_warnings():
+    """Initialize Python warning handling."""
     warnings.simplefilter('default')
     warnings.filterwarnings('ignore', module='pdb', category=ResourceWarning)
-    QtCore.qInstallMessageHandler(qt_message_handler)
 
 
 @contextlib.contextmanager
@@ -182,6 +187,14 @@ def disable_qt_msghandler():
         QtCore.qInstallMessageHandler(old_handler)
 
 
+@contextlib.contextmanager
+def ignore_py_warnings(**kwargs):
+    """Contextmanager to temporarily hke certain Python warnings."""
+    warnings.filterwarnings('ignore', **kwargs)
+    yield
+    _init_py_warnings()
+
+
 def _init_handlers(level, color, force_color, json_logging, ram_capacity):
     """Init log handlers.
 

tests/unit/utils/test_log.py

@@ -23,6 +23,7 @@ import logging
 import argparse
 import itertools
 import sys
+import warnings
 
 import pytest
 import pytest_catchlog
@@ -36,6 +37,7 @@ def restore_loggers():
 
     Based on CPython's Lib/test/test_logging.py.
     """
+    logging.captureWarnings(False)
     logger_dict = logging.getLogger().manager.loggerDict
     logging._acquireLock()
     try:
@@ -278,3 +280,14 @@ def test_stub(caplog, suffix, expected):
         log.stub(suffix)
     assert len(caplog.records) == 1
     assert caplog.records[0].message == expected
+
+
+def test_ignore_py_warnings(caplog):
+    logging.captureWarnings(True)
+    with log.ignore_py_warnings(category=UserWarning):
+        warnings.warn("hidden", UserWarning)
+    with caplog.at_level(logging.WARNING):
+        warnings.warn("not hidden", UserWarning)
+    assert len(caplog.records) == 1
+    msg = caplog.records[0].message.splitlines()[0]
+    assert msg.endswith("UserWarning: not hidden")