Question

我在pydoc中查找了sys，因为我正在阅读的一本书推荐给我，我遇到了last_type这是最后一个未被捕获的异常的类型，我的问题是pydoc / python中什么是未捕获的异常以及它用于什么？

Answer 1

An uncaught exception is just every exception which has not been handled by an except-handler within a try-except statement and hence causes your script to stop.

If this happens the interpreter by default prints the type of the exception, an error message and a traceback.

So if you, for example try to print(1/0), you'll get an exception with type ZeroDivisionError, an error message "division by zero" and the last steps through your code which led to the exception (traceback).

print(1/0)
Traceback (most recent call last):
  File "E:\Programme\Anaconda3\envs\py36\lib\site-
packages\IPython\core\interactiveshell.py", line 2910, in run_code
    exec(code_obj, self.user_global_ns, self.user_ns)
  File "<ipython-input-12-2fc232d1511a>", line 1, in <module>
    print(1/0)
ZeroDivisionError: division by zero

An uncaught exception lets you know that something went wrong. You then have to remove the error source (maybe you actually wanted to write print(1/10), or you have to catch and handle the exception, allowing your program to resume execution of code beneath the error source.

try:
    1/0
except ZeroDivisionError as err:  # error is caught here
    pass # e.g just do nothing
    # print(type(err).__name__, flush=True)  # or do something, like print
                                             # error type

print("will be printed because exception before was caught")

Pydoc Uncaught Exception

1 个答案: