four classes namedException,SystemExit,KeyboardInterrupt andGeneratorExit are derived. All the remaining built-in exception classes are derived directly or indirectly from theException class.The figure shows some of the classes derived fromException class; there are many other classes also. ...
Built-in ExceptionsThe table below shows built-in exceptions that are usually raised in Python:ExceptionDescription ArithmeticError Raised when an error occurs in numeric calculations AssertionError Raised when an assert statement fails AttributeError Raised when attribute reference or assignment fails ...
内建异常(Built-in Exceptions):由Python内部定义的异常,例如ZeroDivisionError、NameError等。 用户自定义异常:由程序员自己定义的异常,用于满足特定的业务需求。 【1】BaseException(所有异常的基类) SystemExit:解释器请求退出 KeyboardInterrupt:用户中断执行(通常是输入^C) Exception:常规错误的基类 StopIteration:迭代器...
Python:built-in exceptions Exception hierarchy¶ The class hierarchy for built-in exceptions is: BaseException +-- SystemExit +-- KeyboardInterrupt +-- GeneratorExit +-- Exception +-- StopIteration +-- StopAsyncIteration +-- ArithmeticError | +-- FloatingPointError | +-- Overfl...
print(e)3、Else in Try-Except 如果没有引发异常,则try-except块中的else子句将运行。这是其他语言没有的 try: # Attempt operation except Exception: # Handle error else: # Executes if no exceptions4、AS关键字 在捕获异常时,可以使用as关键字将异常分配给一个变量,这样可以显示详细信息并使调试更容易。
As a Python developer you can choose to throw an exception if a condition occurs. To throw (or raise) an exception, use theraisekeyword. Example Raise an error and stop the program if x is lower than 0: x = -1 ifx <0: raiseException("Sorry, no numbers below zero") ...
The slice builtin is the type that slice objects have. sorted() staticmethod() class str sum() super() class tuple type() zip()Exceptions exception AssertionError exception AttributeError exception Exception exception ImportError exception IndexError exception KeyboardInterrupt exception KeyError exception...
常见错误3:错误地指定异常代码块(exception block)的参数 请看下面这段代码: 这段代码的问题在于,except语句并不支持以这种方式指定异常。在Python 2.x中,需要使用变量e将异常绑定至可选的第二个参数中,才能进一步查看异常的情况。因此,在上述代码中,except语句并没有捕获IndexError异常;而是将出现的异常绑定到了一...
['__builtins__', '__doc__', '__name__', '__package__'] 可以看到有一个__builtins__的模块名称,这个模块本身定义了一个名称空间,即内建名称空间,我们不妨dir一下: >>> dir(__builtins__) ['ArithmeticError', 'AssertionError', 'AttributeError', 'BaseException', 'BufferError', 'Bytes...
) # Exception: 4 should not be in the expression. 2.4 assert 语句 通过if 语句进行判断,满足条件则触发异常,执行 raise 语句。 if '4' in expression: raise Exception("4 should not be in the expression.") Python 中有 assert 关键词,用它构造一个语句,能够免去 if 和 raise 语句。 assert ('4...