英文:
Do we have a concept of checked and unchecked exceptions in Python?
问题
我的一位在JAVA上工作的朋友问我如何在Python中处理已检查和未检查异常。我以前没有听说过这些术语，所以我在网上搜索了一下，想找出什么是已检查和未检查异常。但我没有找到与这种类型异常相关的任何信息。
> 在Python中是否有已检查和未检查异常的概念？如果没有，那么默认情况下所有的异常是已检查的还是未检查的？
提前感谢你！
英文:
One of my friends who works on JAVA asked me how do I handle checked and unchecked exceptions in Python. I haven't heard these terms before, so I googled around to find out what is checked and unchecked exception. I didn't find anything related to this kind of exception in Python.
> Do we have a concept of checked and unchecked exceptions in Python? If
> no, then by default all the exceptions are checked or unchecked?
Thank you in advance!
答案1
得分: 8
Checked exceptions在Python中并不存在。但是Python在异常类层次结构上有一些相似之处。以下是Java的结构：
在Java中，如果方法可能会抛出Exception或从Exception继承的任何类，但不包括RuntimeException，则必须在方法签名中声明。这个规则被称为checked exceptions。它强制用户考虑这些异常，否则应用程序将无法编译。
在Python中，我们仍然有一个类似的概念，但没有强制执行。你可能听说过，使用裸的except语句是不好的风格，至少你应该选择捕获Exception
try:
foo()
except: # 不好！
bar()
try:
foo()
except Exception: # 稍微好一些！
bar()
这是因为在Python中，Exception继承自BaseException，而裸的except会捕获一切。例如，你可能不希望捕获引发ctrl+c的KeyboardInterrupt。如果你使用裸的except:，那么KeyboardInterrupt会被捕获，但如果你使用except Exception:，你将让其上浮并停止应用程序。这是因为KeyboardInterrupt继承自BaseException而不是Exception，因此不会被捕获！
英文:
Checked exceptions are not a thing in Python. But Python does have some similarities in the exception class hierarchy. Here is the Java structure:
In Java you have to declare in the method signature if the method will throw an Exception or any class that inherits from Exception, but not the RuntimeException. This rule is called checked exceptions.. it forces the user to consider them or the application will not compile.
In Python we still have a similar concept, but no enforcement. You may have heard before that it's bad style to do a bare except statement, and at the very least you should choose to catch Exception
try:
foo()
except: # bad!
bar()
try:
foo()
except Exception: # somewhat better!
bar()
This is because in Python Exception extends from BaseException and a bare except will catch everything. For example, you probably don't want to catch ctrl+c which raises a KeyboardInterrupt. If you do a bare except:, then KeyboardInterrupt will be caught, but if you do a except Exception: you will let this bubble up and stop the application. That is because KeyboardInterrupt extends BaseException and not Exception and therefore wont be caught!
答案2
得分: -1
Java有检查和非检查异常，因为Java是一种编译型编程语言，检查异常在编译时出现。在Python中，没有这样的异常，因为Python是一种解释型语言。
英文:
Java have checked and unchecked exceptions because Java is a complied programming language, checked exception comes in compiling. In python, there is no such exception because Python is an interpreted language.
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