try:
    # 可能引發(fā)異常的代碼
    result = 10 / 0
except ZeroDivisionError:
    # 處理特定異常
    print("不能除以零!")
except Exception as e:
    # 通用異常處理
    print(f"發(fā)生錯(cuò)誤: {e}")
else:
    # 無(wú)異常時(shí)執(zhí)行
    print("計(jì)算成功")
finally:
    # 始終執(zhí)行的清理代碼
    print("清理資源")

BaseException
 ├── KeyboardInterrupt
 ├── SystemExit
 └── Exception
      ├── ArithmeticError
      │    ├── ZeroDivisionError
      │    └── FloatingPointError
      ├── LookupError
      │    ├── IndexError
      │    └── KeyError
      ├── OSError
      │    ├── FileNotFoundError
      │    └── PermissionError
      └── ValueError

# 文件操作
try:
    with open("nonexist.txt") as f:
        content = f.read()
except FileNotFoundError:
    print("文件不存在")

# 類型轉(zhuǎn)換
try:
    num = int("abc")
except ValueError:
    print("無(wú)效的數(shù)字格式")

# 字典操作
d = {"key": "value"}
try:
    print(d["missing"])
except KeyError:
    print("鍵不存在")

try:
    # 可能拋出多種異常的代碼
except (TypeError, ValueError) as e:
    print(f"輸入類型錯(cuò)誤: {e}")

try:
    data = json.loads(invalid_json)
except json.JSONDecodeError:
    print("JSON解析失敗")
except Exception:
    print("其他未知錯(cuò)誤")

file = None
try:
    file = open("data.txt", "r")
    process(file)
except IOError:
    print("文件操作錯(cuò)誤")
finally:
    if file:
        file.close()  # 確保資源釋放

try:
    result = risky_operation()
except NetworkError:
    handle_error()
else:
    save_result(result)  # 僅在成功時(shí)執(zhí)行

class InvalidEmailError(ValueError):
    """自定義郵箱格式異常"""
    def __init__(self, email):
        super().__init__(f"無(wú)效郵箱格式: {email}")
        self.email = email

# 使用示例
email = "user@"
if "@" not in email or "." not in email.split("@")[1]:
    raise InvalidEmailError(email)

class DatabaseError(Exception):
    """數(shù)據(jù)庫(kù)操作基類異常"""

class ConnectionError(DatabaseError):
    """數(shù)據(jù)庫(kù)連接異常"""

class QueryError(DatabaseError):
    """SQL查詢異常"""

try:
    config = load_config()
except FileNotFoundError as e:
    raise RuntimeError("配置加載失敗") from e

try:
    # 可能出錯(cuò)的代碼
except Exception as e:
    print("原始異常:", e.__cause__)
    print("上下文:", e.__context__)

raise ValueError(f"無(wú)效參數(shù)值: {value}")

import logging
try:
    process()
except Exception:
    logging.exception("處理失敗")

try:
    ...
except:  # 捕獲所有異常，包括KeyboardInterrupt
    pass

try:
    ...
except Exception:
    pass  # 靜默失敗

try:
    ...
except Exception as e:
    print(e)
    raise  # 保留原始堆棧信息

import requests
from time import sleep

def fetch_data(url, retries=3):
    for attempt in range(retries):
        try:
            response = requests.get(url, timeout=5)
            response.raise_for_status()
            return response.json()
        except requests.HTTPError as e:
            print(f"HTTP錯(cuò)誤: {e}")
        except requests.Timeout:
            print("請(qǐng)求超時(shí)")
        except requests.RequestException:
            print("網(wǎng)絡(luò)連接問(wèn)題")
        
        if attempt < retries - 1:
            sleep(2 ** attempt)  # 指數(shù)退避
    raise Exception(f"請(qǐng)求失敗，已重試{retries}次")

# 使用示例
data = fetch_data("https://api.example.com/data")