使用Python except捕获所有异常的使用场景

try:
    # 可能引发异常的代码
except:
    # 异常处理逻辑

try:
    with open('data.txt', 'r') as f:
        content = f.read()
except:
    print("文件读取失败，请检查路径是否正确")

except FileNotFoundError:
    print("文件未找到")
except PermissionError:
    print("没有访问权限")

try:
    complex_operation()
except Exception as e:
    print(f"发生未知错误: {str(e)}")
    logging.error(traceback.format_exc())  # 记录详细堆栈信息

import requests

try:
    response = requests.get('https://api.example.com/data', timeout=5)
    response.raise_for_status()
except requests.exceptions.RequestException as e:
    print(f"网络请求失败: {str(e)}")
except Exception as e:
    print(f"其他异常: {str(e)}")

tasks = [task1, task2, task3]

for task in tasks:
    try:
        task.run()
    except Exception as e:
        print(f"任务{task.id}执行失败: {str(e)}")
        continue

while True:
    try:
        user_input = input("请输入数字: ")
        number = int(user_input)
        break
    except ValueError:
        print("输入不是有效的整数，请重试")
    except Exception as e:
        print(f"发生意外错误: {str(e)}")
        break

try:
    result = 100 / 0  # 明显的除零错误
except:
    print("发生错误")  # 掩盖了本应修复的问题

except (requests.ConnectionError, requests.Timeout) as e:
    print("网络连接问题")
except requests.HTTPError as e:
    print("HTTP状态码异常")

try:
    data = fetch_data()
except Exception as e:
    print("错误处理")
else:
    process(data)
finally:
    cleanup_resources()

try:
    try:
        1 / 0
    except ZeroDivisionError as e:
        raise ValueError("数学错误") from e
except Exception as e:
    print(f"异常链: {e.__cause__}")

def handle_error(e, context=""):
    error_type = type(e).__name__
    print(f"[{context}] 错误类型: {error_type}, 信息: {str(e)}")
    # 发送到监控系统...

try:
    risky_operation()
except Exception as e:
    handle_error(e, "主流程")

# 不推荐的写法
for item in large_list:
    try:
        process(item)
    except:
        continue

# 更优方案
valid_items = [item for item in large_list if validate(item)]
for item in valid_items:
    process(item)

import logging
logging.basicConfig(filename='app.log', level=logging.ERROR)

try:
    main_logic()
except Exception as e:
    logging.exception("致命错误发生: %s", str(e))
    # 或者使用详细格式
    logging.error("错误详情", exc_info=True)

class StateMachine:
    def transition(self):
        try:
            self.validate_transition()
        except PreconditionError as e:
            self.handle_validation_error(e)
        except Exception as e:
            self.handle_unexpected_error(e)
        else:
            self.execute_transition()

def safe_execute(func):
    def wrapper(*args, **kwargs):
        try:
            return func(*args, **kwargs)
        except ValueError as e:
            print(f"值错误: {str(e)}")
        except Exception as e:
            print(f"未知错误: {str(e)}")
    return wrapper

@safe_execute
def calculate(data):
    # 业务逻辑

import unittest

class TestErrorHandling(unittest.TestCase):
    def test_division(self):
        with self.assertRaises(ZeroDivisionError):
            1 / 0

    def test_custom_error(self):
        with self.assertRaisesRegex(ValueError, "必须为正数"):
            check_value(-5)

def run_tasks():
    with allow_unhandled():
        task1()
        task2()

try:
    run_tasks()
except* ValueError as e:
    print(f"值错误组: {e.exceptions}")

from contextlib import contextmanager

@contextmanager
def safe_open(filename):
    try:
        f = open(filename, 'r')
        yield f
    except FileNotFoundError:
        print("文件未找到")
    finally:
        if 'f' in locals():
            f.close()

from tenacity import retry, stop_after_attempt, wait_exponential

@retry(stop=stop_after_attempt(3), wait=wait_exponential(multiplier=1))
def fetch_data():
    # 可能失败的网络请求