Python中异常处理：10大常见异常及其处理实例-向日葵屋

Python中异常处理：10大常见异常及其处理实例

原创悠悠 2025-02-24 12:30 41阅读 0赞

在Python编程中，异常处理是一种机制，用于在程序执行过程中遇到错误时进行适当的处理。以下是Python中10种常见的异常以及相应的处理实例：

ZeroDivisionError：当除数为零时引发。示例：

try:
    division = 1 / 0
except ZeroDivisionError as e:
    print(f"Error: {e}. Avoid dividing by zero.")

TypeError：当操作或函数应用于不合适的类型时引发。示例：

try:
    int_string = "32"
    float_number = int_string + ".5"
    print(float_number)
except TypeError as e:
    print(f"Error: {e}. Type conversion may be required.")

ValueError：当数据不符合预期格式时引发。示例：

try:
    email = "invalid-email"
    validate_email(email)
except ValueError as e:
    print(f"Error: {e}. Email validation failed.")

KeyError：当试图访问字典中不存在的键时引发。示例：

try:
    my_dict = {"name": "Alice", "age": 25}
    print(my_dict["address"]))
except KeyError as e:
    print(f"Error: {e}. Key 'address' not found in dictionary.")

IndexError：当尝试访问列表中的某个索引超出范围时引发。示例：

try:
    my_list = [1, 2, 3]
    print(my_list[4])
except IndexError as e:
    print(f"Error: {e}. Index '4' is out of range for list.")

FileNotFoundError：当尝试打开一个不存在的文件时引发。示例：

try:
    file_to_open = "nonexistent_file.txt"
    with open(file_to_open, 'r') as f:
        print(f.read())
except FileNotFoundError as e:
    print(f"Error: {e}. File 'nonexistent_file.txt' not found.")

IOError：这是FileNotFoundError的父类，当文件操作遇到更广泛的错误时引发。示例：

try:
    file_to_open = "broken_file"
    with open(file_to_open, 'r') as f:
        print(f.read())
except IOError as e:
    print(f"Error: {e}. File 'broken_file' could not be opened due to an error.")

SystemExit：在Python中，当调用os.system()或sys.exit()时会引发。示例：

try:
    exit_message = "Program gracefully stopped."
    os.system("echo " + exit_message)
    sys.exit(0)  # Normal exit, no error code
except SystemExit as e:
    print(f"Error: {e}. Program was terminated via 'sys.exit()'.")

Timeout：当使用time.sleep()或其他可能导致阻塞的操作时，可能会遇到超时问题。示例：

try:
    time_to_wait = 5  # seconds
    sleep(time_to_wait)
    print("Action completed within the timeout.")
except TimeoutError as e:
    print(f"Error: {e}. Action timed out after '{time_to_wait}' seconds.".format(time_to_wait)))

SyntaxError：当Python解析器遇到语法错误时，会引发此错误。示例：

try:
    invalid_code = "print('Hello, World!')\ninvalid_line"
    exec(invalid_code)  # Raises SyntaxError
   except SyntaxError as e:
       print(f"Error: {e}. Invalid syntax found in code.".format(invalid_code)))