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@nyk510
Last active August 1, 2020 07:54
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{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# About\n",
"\n",
"logging で `info` とかで出したものを文字列として取得したい!"
]
},
{
"cell_type": "code",
"execution_count": 1,
"metadata": {},
"outputs": [],
"source": [
"from logging import getLogger, StreamHandler, Formatter"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"### 下準備\n",
"\n",
"* 単純な logger と stream handler (コンソールへの出力のハンドラ) を用意します。\n",
"* 詳しくは https://docs.python.org/ja/3/howto/logging.html#logging-advanced-tutorial など参考に"
]
},
{
"cell_type": "code",
"execution_count": 2,
"metadata": {},
"outputs": [],
"source": [
"handler = StreamHandler()\n",
"handler.setLevel('INFO')\n",
"\n",
"logger = getLogger('nyk.510')\n",
"logger.setLevel('INFO')\n",
"logger.addHandler(handler)"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"`INFO` level が設定されているので `INFO` よりも重要度が高いものが logging として output される.\n",
"\n",
"> https://docs.python.org/ja/3/howto/logging.html#loggers \n",
"> 組み込みの深刻度の中では DEBUG が一番低く、 CRITICAL が一番高くなります。たとえば、深刻度が INFO と設定されたロガーは INFO, WARNING, ERROR, CRITICAL のメッセージしか扱わず、 DEBUG メッセージは無視します。"
]
},
{
"cell_type": "code",
"execution_count": 3,
"metadata": {},
"outputs": [
{
"name": "stderr",
"output_type": "stream",
"text": [
"warn\n",
"foo\n"
]
}
],
"source": [
"logger.warning('warn')\n",
"logger.info('foo')\n",
"\n",
"logger.debug('debug') # debug はでないよ"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"### logging をテキストとしてとる\n",
"\n",
"StringIO を stream にもつような handler を作成して設定する"
]
},
{
"cell_type": "code",
"execution_count": 4,
"metadata": {},
"outputs": [],
"source": [
"import io"
]
},
{
"cell_type": "code",
"execution_count": 5,
"metadata": {},
"outputs": [],
"source": [
"log_capture_io = io.StringIO()\n",
"stream_handler = StreamHandler(stream=log_capture_io)\n",
"\n",
"# オシャに formatting\n",
"formatter = Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')\n",
"stream_handler.setFormatter(formatter)\n",
"\n",
"stream_handler.setLevel('INFO')\n",
"logger.addHandler(stream_handler)"
]
},
{
"cell_type": "code",
"execution_count": 6,
"metadata": {},
"outputs": [
{
"name": "stderr",
"output_type": "stream",
"text": [
"hoge\n",
"bar\n"
]
}
],
"source": [
"logger.info('hoge')\n",
"logger.info('bar')"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"### log の取得\n",
"\n",
"作成した IO から `getvalue` すればOK\n",
"\n",
"* 通常のコンソールアウトプットは単に文字列だったが, `formatter` をリッチにしているので取得される文字列には何時 log が記録されたかなどの情報も入っている\n",
"* コンソールの方も普通の `StreamHandler` に formatter を設定すれば時間も表示できる."
]
},
{
"cell_type": "code",
"execution_count": 7,
"metadata": {},
"outputs": [
{
"data": {
"text/plain": [
"['2020-08-01 07:42:26,918 - nyk.510 - INFO - hoge',\n",
" '2020-08-01 07:42:26,920 - nyk.510 - INFO - bar']"
]
},
"execution_count": 7,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"s = log_capture_io.getvalue()\n",
"s.splitlines()"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"### 後片付け\n",
"\n",
"ずっと handler が付いていると記録され続けるので、いらなくなったら消しましょう\n",
"\n",
"* io の close\n",
"* handler のひも付けを logger から削除 `removeHandler`"
]
},
{
"cell_type": "code",
"execution_count": 8,
"metadata": {},
"outputs": [],
"source": [
"# 終わったら消しましょう\n",
"log_capture_io.close()\n",
"logger.removeHandler(stream_handler)"
]
},
{
"cell_type": "code",
"execution_count": 9,
"metadata": {},
"outputs": [
{
"data": {
"text/plain": [
"True"
]
},
"execution_count": 9,
"metadata": {},
"output_type": "execute_result"
}
],
"source": [
"log_capture_io.closed"
]
},
{
"cell_type": "code",
"execution_count": 10,
"metadata": {},
"outputs": [
{
"ename": "ValueError",
"evalue": "I/O operation on closed file",
"output_type": "error",
"traceback": [
"\u001b[0;31m---------------------------------------------------------------------------\u001b[0m",
"\u001b[0;31mValueError\u001b[0m Traceback (most recent call last)",
"\u001b[0;32m<ipython-input-10-b5f4bf9c6e8d>\u001b[0m in \u001b[0;36m<module>\u001b[0;34m\u001b[0m\n\u001b[0;32m----> 1\u001b[0;31m \u001b[0mlog_capture_io\u001b[0m\u001b[0;34m.\u001b[0m\u001b[0mgetvalue\u001b[0m\u001b[0;34m(\u001b[0m\u001b[0;34m)\u001b[0m\u001b[0;34m\u001b[0m\u001b[0;34m\u001b[0m\u001b[0m\n\u001b[0m",
"\u001b[0;31mValueError\u001b[0m: I/O operation on closed file"
]
}
],
"source": [
"log_capture_io.getvalue()"
]
}
],
"metadata": {
"kernelspec": {
"display_name": "Python 3",
"language": "python",
"name": "python3"
},
"language_info": {
"codemirror_mode": {
"name": "ipython",
"version": 3
},
"file_extension": ".py",
"mimetype": "text/x-python",
"name": "python",
"nbconvert_exporter": "python",
"pygments_lexer": "ipython3",
"version": "3.7.7"
}
},
"nbformat": 4,
"nbformat_minor": 4
}
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