さらに調査を行ったところ、それを達成するための完璧な方法が見つかりました。
のソースコードを見るlogging.captureWarnings()
:
def captureWarnings(capture):
"""
If capture is true, redirect all warnings to the logging package.
If capture is False, ensure that warnings are not redirected to logging
but to their original destinations.
"""
global _warnings_showwarning
if capture:
if _warnings_showwarning is None:
_warnings_showwarning = warnings.showwarning
warnings.showwarning = _showwarning
else:
if _warnings_showwarning is not None:
warnings.showwarning = _warnings_showwarning
_warnings_showwarning = None
warnings.showwarning
必要なロギングジョブ(またはその他のこと)を実行する別の呼び出し可能オブジェクトを指すように変更できるようです。
の予想されるプロトタイプは次のwarnings.showwarning
ようです。
def _show_warning(message, category, filename, lineno, file=None, line=None):
"""Hook to write a warning to a file; replace if you like."""
if file is None:
file = sys.stderr
try:
file.write(formatwarning(message, category, filename, lineno, line))
except IOError:
pass # the file (probably stderr) is invalid - this warning gets lost.
logging.captureWarnings()
実際には callable を次のように設定しているようですlogging._showwarning
:
def _showwarning(message, category, filename, lineno, file=None, line=None):
"""
Implementation of showwarnings which redirects to logging, which will first
check to see if the file parameter is None. If a file is specified, it will
delegate to the original warnings implementation of showwarning. Otherwise,
it will call warnings.formatwarning and will log the resulting string to a
warnings logger named "py.warnings" with level logging.WARNING.
"""
if file is not None:
if _warnings_showwarning is not None:
_warnings_showwarning(message, category, filename, lineno, file, line)
else:
s = warnings.formatwarning(message, category, filename, lineno, line)
logger = getLogger("py.warnings")
if not logger.handlers:
logger.addHandler(NullHandler())
logger.warning("%s", s)