如何使用日志記錄在Flask路由中記錄未捕獲的例外？

在 Flask 路由中記錄未捕獲運算式的標準方法是什么logging？

這幾乎有效：

import logging, sys, flask
logging.basicConfig(filename='test.log', filemode='a', format='%(asctime)s %(levelname)s %(message)s')
sys.excepthook = lambda exctype, value, tb: logging.error("", exc_info=(exctype, value, tb))
logging.warning("hello")
app = flask.Flask('hello')
@app.route('/')
def index():
    sjkfq          # uncaught expresion
    return "hello"
app.run()

但日志中有一些 ANSI 轉義字符：[31m[1m等（可能用于控制臺顏色）

test.log在生成的檔案中查看此處：

2022-10-21 16:23:06,817 WARNING hello
2022-10-21 16:23:07,096 INFO [31m[1mWARNING: This is a development server. Do not use it in a production deployment. Use a production WSGI server instead.[0m
 * Running on http://127.0.0.1:5000
2022-10-21 16:23:07,097 INFO [33mPress CTRL C to quit[0m
2022-10-21 16:23:07,691 ERROR Exception on / [GET]
Traceback (most recent call last):
  File "C:\Python38\lib\site-packages\flask\app.py", line 2525, in wsgi_app
    response = self.full_dispatch_request()
  File "C:\Python38\lib\site-packages\flask\app.py", line 1822, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "C:\Python38\lib\site-packages\flask\app.py", line 1820, in full_dispatch_request
    rv = self.dispatch_request()
  File "C:\Python38\lib\site-packages\flask\app.py", line 1796, in dispatch_request
    return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)
  File "D:\test.py", line 10, in index
    sjkfq
NameError: name 'sjkfq' is not defined
2022-10-21 16:23:07,694 INFO 127.0.0.1 - - [21/Oct/2022 16:23:07] "[35m[1mGET / HTTP/1.1[0m" 500 -

請注意，如果您運行相同的代碼，這是完全可重現的。

是否有記錄的方法可以使用 Python 正確記錄 Flask 路由中未捕獲的例外logging？我在https://flask.palletsprojects.com/en/2.2.x/logging/中沒有完全找到這個。

（注意：這段代碼表明它不是正確的記錄方式。我們不應該截取記錄字串，做一些逆向工程來清除轉義字符，然后記錄到檔案。肯定有標準的記錄方式。）

uj5u.com熱心網友回復：

所以問題是那些 ANSII 字符[31m[1m指定終端中訊息的顏色。

據我了解，Flask 從 werkzeug 獲取日志并添加一些顏色。

正如您從這個問題中看到的那樣，沒有辦法通過設定中的任何簡單標志來禁用燒瓶日志記錄中的著色（不幸的是）

您可以做的是添加格式化程式，該格式化程式將在記錄之前獲取訊息并洗掉顏色樣式。

import logging, sys, flask
import click


class NoColorFormatter(logging.Formatter):
    def format(self, record: logging.LogRecord) -> str:
        return click.unstyle(super().format(record))


werkzeug_logger = logging.getLogger("werkzeug")
root_logger = logging.getLogger()

handler = logging.FileHandler("test.log")
handler.setFormatter(NoColorFormatter("%(asctime)s %(levelname)s %(message)s"))
werkzeug_logger.addHandler(handler)
root_logger.addHandler(handler)

sys.excepthook = lambda exctype, value, tb: logging.error(
    "", exc_info=(exctype, value, tb)
)

logging.warning("hello")

app = flask.Flask("hello")


@app.route("/")
def index():
    sjkfq  # uncaught expresion
    return "hello"


if __name__ == "__main__":
    app.run()

uj5u.com熱心網友回復：

我使用裝飾器來捕獲例外，這也可以記錄錯誤：

from flask import abort
from functools import wraps


def catch_uncaught(function):
"""
catches uncaught exceptions and logs them
aborts the request
"""

    @wraps(function)
    def wrapper(*args, **kwargs):
        try:
            res = function(*args, **kwargs)
            return res  # no errors occurred
        except Exception as e:
            # log stack trace
            logging.error("\n"   traceback.format_exc()   "\n")
            # abort the request instead of crashing
            abort(500, "Internal Server error, do not retry")
    return wrapper

（這也將中止請求而不是使服務器崩潰 - 但這是“可選的”。如果您更喜歡崩潰，return function(*args, **kwargs)在記錄而不是中止之后）

然后，您可以將此裝飾器放在要捕獲例外的路由之上以記錄它們：

@app.route("/")
@catch_uncaught
def index():
    sjkfq  # uncaught exception
    return "hello"

這可能不是標準方式，但效果很好

uj5u.com熱心網友回復：

問題隱藏在燒瓶罩下的 werkzeug 服務器中。如果我們修補變數werkzeug.serving._log_add_style那么函式_ansi_style將不會改變任何日志條目的顏色。

import flask
import logging
import werkzeug.serving
werkzeug.serving._log_add_style = False
logging.basicConfig(filename='test.log', filemode='a', format='%(asctime)s %(levelname)s %(message)s')
logging.warning("hello")
app = flask.Flask("hello")
@app.route("/")
def index():
    sjkfq  # uncaught expression
    return "hello"
app.run()

日志看起來像這樣

2022-10-27 18:31:56,193 WARNING hello
2022-10-27 18:31:56,199 INFO WARNING: This is a development server. Do not use it in a production deployment. Use a production WSGI server instead.
 * Running on http://127.0.0.1:5000
2022-10-27 18:31:56,199 INFO Press CTRL C to quit
2022-10-27 18:32:01,920 ERROR Exception on / [GET]
Traceback (most recent call last):
  File "/Users/me/.env/test/lib/python3.8/site-packages/flask/app.py", line 2525, in wsgi_app
response = self.full_dispatch_request()
  File "/Users/me/.env/test/lib/python3.8/site-packages/flask/app.py", line 1822, in full_dispatch_request
rv = self.handle_user_exception(e)
  File "/Users/me/.env/test/lib/python3.8/site-packages/flask/app.py", line 1820, in full_dispatch_request
rv = self.dispatch_request()
  File "/Users/me/.env/test/lib/python3.8/site-packages/flask/app.py", line 1796, in dispatch_request
return self.ensure_sync(self.view_functions[rule.endpoint])(**view_args)
  File "flask_logging.py", line 10, in index
sjkfq  # uncaught expression
NameError: name 'sjkfq' is not defined
2022-10-27 18:32:01,922 INFO 127.0.0.1 - - [27/Oct/2022 18:32:01] "GET / HTTP/1.1" 500 -

標籤：Python烧瓶日志记录蟒蛇日志

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