自定义异常：程序员可以根据需要创建自己的异常类，通常继承自内置的异常基类（如 Exception），以便更精确地表示应用程序特有的错误条件。 2. 异常的引发（raise）使用 raise 语句可以主动引发一个异常。这在编写自定义函数或方法时特别有用，当特定条件不满足或发生预期之外的情况时，通过抛出异常通知调用者。def
Example 6: Using 'raise' to Re-Raise Exceptions This example demonstrates how to re-raise an exception after handling it partially. The 'open_file' function attempts to open a file and raises a 'FileNotFoundError' if the file does not exist. The exception is caught, logged, and then re...
print("处理异常") 抛出异常类:raise MyException('文件找不到') """ import datetime as dt def read_date(in_date): try: date = dt.datetime.strptime(in_date, '%Y-%m-%d') return date except ValueError as e: print(e) print('处理ValueError异常') str_date = '201B-8-18' print('日期 ...
raise [Exception [, args [, traceback]]] # eg:raise NotImplementedError("Not Implemented") x = 10 if x > 5: raise Exception('x 不能大于 5。x 的值为: {}'.format(x)) >>> try: raise NameError('HiThere') # 模拟一个异常。 except NameError: print('An exception flew by!') rais...
In contrast, Python encourages you to raise exceptions, which you handle.Note: In Python, not all exceptions are errors. The built-in StopIteration exception is an excellent example of this. Python internally uses this exception to terminate the iteration over iterators. Python exceptions that ...
try:# 尝试执行可能会出现异常的代码file=open('example.txt','r')# 处理文件内容exceptFileNotFoundError:# 处理文件未找到异常print("文件未找到")finally:# 关闭文件file.close() raise 关键字:raise关键字用于手动引发异常,开发者可以使用它来触发特定类型的异常。
Here, while trying to divide7 / 0, the program throws a system exceptionZeroDivisionError Python Built-in Exceptions Illegal operations can raise exceptions. There are plenty of built-in exceptions in Python that are raised when corresponding errors occur. ...
raise InsufficientBalanceError("余额不足") # 执行转账操作...1.3 Python语言中的异常体系概览 在Python的世界观里,异常被组织成了一棵类别层次结构。最顶层的是BaseException,它是所有异常类型的基类。常见的内置异常如ValueError、TypeError、FileNotFoundError等都继承自Exception类,而更严重的系统退出异常SystemExit、...
except Exception as e: print(f'error is {str(e)}') pass # 2 - better import traceback try: func(data) except Exception: self.output("raise exception, stop backtesting") # self.output(traceback.format_exc()) self.output(traceback.print_exc()) ...
Raise an exceptionAs a Python developer you can choose to throw an exception if a condition occurs.To throw (or raise) an exception, use the raise keyword.ExampleGet your own Python Server Raise an error and stop the program if x is lower than 0: x = -1if x < 0: raise Exception(...