Python 仅从回溯中提取异常

Question

我有嵌套的 python 异常。我不想将它们全部从回溯中提取到列表中，同时丢弃其他所有内容，即文件、代码行等。

下面的代码从回溯中提取所有内容作为字符串列表

import traceback
import requests


try:
    r = requests.get('https://thisdoesntexist.test')
except Exception as e:
    exc = traceback.format_exception(e)

print(exc)

输出：

[
    'Traceback (most recent call last):\n',
    '  File "c:\\Python312\\Lib\\site-packages\\urllib3\\connection.py", line 203, in _new_conn\n    sock = connection.create_connection(\n           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n',
    '  File "c:\\Python312\\Lib\\site-packages\\urllib3\\util\\connection.py", line 60, in create_connection\n    for res in socket.getaddrinfo(host, port, family, socket.SOCK_STREAM):\n               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n',
    '  File "c:\\Python312\\Lib\\socket.py", line 963, in getaddrinfo\n    for res in _socket.getaddrinfo(host, port, family, type, proto, flags):\n               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^\n',
    'socket.gaierror: [Errno 11001] getaddrinfo failed\n',
    '\nThe above exception was the direct cause of the following exception:\n\n',
    'Traceback (most recent call last):\n',
  
    # Output truncated

    'requests.exceptions.ConnectionError: HTTPSConnectionPool(host=\'thisdoesntexist.test\', port=443): Max retries exceeded with url: / (Caused by NameResolutionError("<urllib3.connection.HTTPSConnection object at 0x0000025E6C236600>: Failed to resolve \'thisdoesntexist.test\' ([Errno 11001] getaddrinfo failed)"))\n'
]

但我只需要这个：

[
    'socket.gaierror: [Errno 11001] getaddrinfo failed',
    'urllib3.exceptions.NameResolutionError: <urllib3.connection.HTTPSConnection object at 0x0000025E6C236600>: Failed to resolve 'thisdoesntexist.test' ([Errno 11001] getaddrinfo failed)',
    'urllib3.exceptions.MaxRetryError: HTTPSConnectionPool(host=\'thisdoesntexist.test\', port=443): Max retries exceeded with url: / (Caused by NameResolutionError("<urllib3.connection.HTTPSConnection object at 0x0000025E6C236600>: Failed to resolve \'thisdoesntexist.test\' ([Errno 11001] getaddrinfo failed)"))',
    'requests.exceptions.ConnectionError: HTTPSConnectionPool(host=\'thisdoesntexist.test\', port=443): Max retries exceeded with url: / (Caused by NameResolutionError("<urllib3.connection.HTTPSConnection object at 0x0000025E6C236600>: Failed to resolve \'thisdoesntexist.test\' ([Errno 11001] getaddrinfo failed)"))\n'
]

是否有更好的方法来实现这一目标，而无需迭代字符串和模式匹配？

注意： 如果除了异常消息字符串之外我还能获取异常的类型，那就完美了，例如：

[
    {"type": "socket.gaierror", "message": 'socket.gaierror: [Errno 11001] getaddrinfo failed'},
    {"type": "urllib3.exceptions.NameResolutionError", "message": 'urllib3.exceptions.NameResolutionError: <urllib3.connection.HTTPSConnection object at 0x0000025E6C236600>: Failed to resolve \'thisdoesntexist.test\' ([Errno 11001] getaddrinfo failed)'},

    # etc

]

Answer 1

你可以尝试：

import traceback

import requests


def get_info(exc):
    r = []

    if exc.__context__:
        r += get_info(exc.__context__)

    tbe = traceback.TracebackException.from_exception(exc)

    r.append({"type": tbe.exc_type.__name__, "message": str(exc)})
    return r


try:
    r = requests.get("https://thisdoesntexist.test")
except Exception as e:
    print(get_info(e))

打印：

[
    {"type": "gaierror", "message": "[Errno -2] Name or service not known"},
    {
        "type": "NameResolutionError",
        "message": "<urllib3.connection.HTTPSConnection object at 0x7fcc18e014d0>: Failed to resolve 'thisdoesntexist.test' ([Errno -2] Name or service not known)",
    },
    {
        "type": "MaxRetryError",
        "message": "HTTPSConnectionPool(host='thisdoesntexist.test', port=443): Max retries exceeded with url: / (Caused by NameResolutionError(\"<urllib3.connection.HTTPSConnection object at 0x7fcc18e014d0>: Failed to resolve 'thisdoesntexist.test' ([Errno -2] Name or service not known)\"))",
    },
    {
        "type": "ConnectionError",
        "message": "HTTPSConnectionPool(host='thisdoesntexist.test', port=443): Max retries exceeded with url: / (Caused by NameResolutionError(\"<urllib3.connection.HTTPSConnection object at 0x7fcc18e014d0>: Failed to resolve 'thisdoesntexist.test' ([Errno -2] Name or service not known)\"))",
    },
]