不灭的火

Python中的traceback模块被用于跟踪异常返回信息，可以在logging中记录下traceback：

import logging

logger = logging.getLogger(__name__)
logger.setLevel(level = logging.INFO)
handler = logging.FileHandler("log.txt")
handler.setLevel(logging.INFO)
formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
handler.setFormatter(formatter)
 
console = logging.StreamHandler()
console.setLevel(logging.INFO)
 
logger.addHandler(handler)
logger.addHandler(console)
 
logger.info("Start print log")
logger.debug("Do something")
logger.warning("Something maybe fail.")

try:
    open("sklearn.txt", "rb")
except (SystemExit, KeyboardInterrupt):
    raise
except Exception:
    logger.error("Faild to open sklearn.txt from logger.error", exc_info = True)
 
logger.info("Finish")
 
#在这里也可以将日志捕获异常编写成一个通用类，然后尽量分各种类型的traceback去编写捕获方法

也可以使用 logger.exception(msg, _args)，它等价于 logger.error(msg, exc_info=True, _args)

将

logger.error("Faild to open sklearn.txt from logger.error", exc_info=True)

修改为：

logger.exception("Failed to open sklearn.txt from logger.exception")

控制台 和 日志文件log.txt中输出：

Start print log
Something maybe fail.
Failed to open sklearn.txt from logger.exception
Traceback (most recent call last):
  File "G:\zhb7627\Code\Eclipse WorkSpace\PythonTest\test.py", line 23, in <module>
    open("sklearn.txt","rb")
IOError: [Errno 2] No such file or directory: 'sklearn.txt'
Finish

后面把堆栈信息也 放出来了，方便跟踪业务代码的调用方法链，（部分）参考代码如下：

def execute(self, sql):
    """
    插入、修改、删除 等执行操作
    :param sql: SQL字符串
    :return: 成功则返回新插入数据的主键ID 或 受影响的行数，失败返回False
    """
    if self.__auto_commit is False:
        return self.__execute(sql)
    else:
        try:
            ret = self.__execute(sql)
            self.__conn.commit()
            return ret
        except pymysql.Error as e:
            self.__conn.rollback()
            err_msg = string_str(e) + "\n" + sql
            logger.exception(err_msg, stack_info=True)  # 【注意】把stack堆栈信息也打印出来
            return False

异常时输出：

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
2020-10-08 10:23:26,774 [ERROR] mysql.py:130
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
(1146, "Table 'jianbao_blog.bookmarks' doesn't exist")
UPDATE bookmarks SET stock_name='\'顺丰股份\'' WHERE stock_no='300002'
Traceback (most recent call last):
  File "D:\python\PyCharmProjects\wenjianbao\jianbao_blog\framework\utils\database\mysql.py", line 124, in execute
    ret = self.__execute(sql)
  File "D:\python\PyCharmProjects\wenjianbao\jianbao_blog\framework\utils\database\mysql.py", line 102, in __execute
    cursor.execute(sql)
  File "D:\python\Anaconda3\lib\site-packages\pymysql\cursors.py", line 163, in execute
    result = self._query(query)
  File "D:\python\Anaconda3\lib\site-packages\pymysql\cursors.py", line 321, in _query
    conn.query(q)
  File "D:\python\Anaconda3\lib\site-packages\pymysql\connections.py", line 505, in query
    self._affected_rows = self._read_query_result(unbuffered=unbuffered)
  File "D:\python\Anaconda3\lib\site-packages\pymysql\connections.py", line 724, in _read_query_result
    result.read()
  File "D:\python\Anaconda3\lib\site-packages\pymysql\connections.py", line 1069, in read
    first_packet = self.connection._read_packet()
  File "D:\python\Anaconda3\lib\site-packages\pymysql\connections.py", line 676, in _read_packet
    packet.raise_for_error()
  File "D:\python\Anaconda3\lib\site-packages\pymysql\protocol.py", line 223, in raise_for_error
    err.raise_mysql_exception(self._data)
  File "D:\python\Anaconda3\lib\site-packages\pymysql\err.py", line 107, in raise_mysql_exception
    raise errorclass(errno, errval)
pymysql.err.ProgrammingError: (1146, "Table 'jianbao_blog.bookmarks' doesn't exist")
Stack (most recent call last):
  File "D:/python/PyCharmProjects/wenjianbao/jianbao_blog/_tests/database/mysql_update.py", line 6, in <module>
    res = db.update("bookmarks", {
  File "D:\python\PyCharmProjects\wenjianbao\jianbao_blog\framework\utils\database\mysql.py", line 175, in update
    return self.execute(sql)
  File "D:\python\PyCharmProjects\wenjianbao\jianbao_blog\framework\utils\database\mysql.py", line 130, in execute
    logger.exception(err_msg, stack_info=True)

Process finished with exit code 0