raise 異常類(lèi)型(錯(cuò)誤信息)

def divide(a, b):
    if b == 0:
        # ValueError是內(nèi)置的異常類(lèi)型，就不需要自己定義了
        raise ValueError("除數(shù)不能為零")
    return a / b
try:
    result = divide(10, 0)
except ValueError as e:
    print(f"捕獲到錯(cuò)誤: {e}")

def get_element(lst, index):
    if index >= len(lst):
        # IndexError錯(cuò)誤類(lèi)型因?yàn)樗揪陀兴圆挥胏lass定義
        raise IndexError("索引超出列表范圍")
    return lst[index]
# 使用
try:
    get_element([1, 2, 3], 5)
except IndexError as e:
    print(e)  # 輸出：索引超出列表范圍

try:
    10 / 0
except ZeroDivisionError:
    print("發(fā)生了除以零錯(cuò)誤，記錄日志后重新拋出")
    raise  # 重新拋出相同的異常

def process_file(filename):
    try:
        with open(filename) as f:
            return f.read()
    except IOError as e:
        raise RuntimeError("文件處理失敗") from e
try:
    process_file("nonexistent.txt")
except RuntimeError as e:
    print(f"主錯(cuò)誤: {e}")
    print(f"原始原因: {e.__cause__}")  # 訪問(wèn)原始異常

# 自定義一個(gè)異常類(lèi)型（InvalidEmailError），以及異常消息
class InvalidEmailError(Exception):
    """當(dāng)電子郵件格式無(wú)效時(shí)拋出"""
    pass
def send_email(email):
    if "@" not in email:
        raise InvalidEmailError(f"無(wú)效的郵箱地址: {email}")
    # 發(fā)送郵件邏輯...
try:
    send_email("userexample.com")  # 缺少@符號(hào)
except InvalidEmailError as e:
    print(f"郵件發(fā)送失敗: {e}")

class TemperatureError(Exception):
    def __init__(self, temp, min_temp, max_temp):
        self.temp = temp
        self.min_temp = min_temp
        self.max_temp = max_temp
        super().__init__(f"溫度{temp}超出范圍({min_temp}-{max_temp})")
def check_temperature(temp):
    if not (0 <= temp <= 100):
        raise TemperatureError(temp, 0, 100)
    print("溫度正常")
try:
    check_temperature(-5)
except TemperatureError as e:
    print(f"錯(cuò)誤溫度: {e.temp}, 允許范圍: {e.min_temp}-{e.max_temp}")

def process_age(age):
    if not isinstance(age, int):
        raise TypeError("年齡必須是整數(shù)")
    if age < 0:
        raise ValueError("年齡不能為負(fù)數(shù)")
    if age < 18:
        print("未成年人")
    else:
        print("成年人")
# 測(cè)試
for age in [15, 25, -3, "20"]:
    try:
        process_age(age)
    except (TypeError, ValueError) as e:
        print(f"無(wú)效輸入: {e}")

def calculate_average(numbers):
    assert len(numbers) > 0, "數(shù)字列表不能為空"
    return sum(numbers) / len(numbers)
# 等同于
def calculate_average(numbers):
    if len(numbers) == 0:
        raise ValueError("數(shù)字列表不能為空")
    return sum(numbers) / len(numbers)

def create_user(username, email):
    if not username:
        raise ValueError("用戶名不能為空")
    if len(username) < 3:
        raise ValueError("用戶名至少需要3個(gè)字符")
    if "@" not in email:
        raise ValueError("無(wú)效的郵箱格式")
    print(f"創(chuàng)建用戶: {username}, 郵箱: {email}")
try:
    create_user("ab", "invalid-email")
except ValueError as e:
    print(f"用戶創(chuàng)建失敗: {e}")

class DatabaseError(Exception):
    pass
class ConnectionError(DatabaseError):
    pass
class QueryError(DatabaseError):
    pass
def execute_query(query):
    if not query.startswith("SELECT"):
        raise QueryError("只支持SELECT查詢")
    # 模擬連接失敗
    if "fail" in query:
        raise ConnectionError("數(shù)據(jù)庫(kù)連接失敗")
    print(f"執(zhí)行查詢: {query}")
queries = ["SELECT * FROM users", "UPDATE users", "SELECT fail"]
for query in queries:
    try:
        execute_query(query)
    except ConnectionError as e:
        print(f"連接問(wèn)題: {e}")
    except QueryError as e:
        print(f"查詢錯(cuò)誤: {e}")