blocks|key|4459887|text|如果查看documentation+for+the+built-in+errors，您将看到大多数Exception类将其第一个参数指定为message属性。然而，并不是所有人都这样做。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4459888|值得注意的是，EnvironmentError+(具有子类IOError和OSError)的第一个参数为errno，第二个参数为strerror。没有message……strerror大致类似于通常的message。|4459889|更广泛地说，Exception的子类可以做他们想做的任何事情。它们可能有也可能没有message属性。未来的内置Exception%25s可能没有message属性。从第三方库或用户代码导入的任何Exception子类都不能具有message属性。|4459890|我认为处理这个问题的正确方法是确定您想要捕获的特定Exception子类，然后只捕获这些子类，而不是使用except+Exception捕获所有子类，然后以您希望的方式利用特定子类定义的任何属性。|4459891|如果您必须print一些东西，我认为打印捕获的Exception本身最有可能做您想做的事情，无论它是否具有message属性。|4459892|如果您愿意，也可以检查message属性，如下所示，但我不建议这样做，因为它看起来很混乱：|4459893|try:
++++pass
except+Exception+as+e:
++++#+Just+print(e)+is+cleaner+and+more+likely+what+you+want,
++++#+but+if+you+insist+on+printing+message+specifically+whenever+possible...
++++if+hasattr(e,+'message'):
++++++++print(e.message)
++++else:
++++++++print(e)|code-block|syntax|javascript|4459894|entityMap|0|LINK|mutability|MUTABLE|url|https://docs.python.org/2/library/exceptions.html^0|1D|9|1X|7|4|11|0|0|7|G|T|7|11|7|1G|5|1S|8|23|7|2C|8|2S|7|0|6|9|15|7|1K|9|1Z|7|2O|9|34|7|0|P|9|1G|G|0|5|5|N|9|1H|7|0|0|0^^$0|@$1|2|3|4|5|6|7|12|8|@$9|13|A|14|B|C]|$9|15|A|16|B|C]]|D|@$9|17|A|18|1|19]]|E|$]]|$1|F|3|G|5|6|7|1A|8|@$9|1B|A|1C|B|C]|$9|1D|A|1E|B|C]|$9|1F|A|1G|B|C]|$9|1H|A|1I|B|C]|$9|1J|A|1K|B|C]|$9|1L|A|1M|B|C]|$9|1N|A|1O|B|C]|$9|1P|A|1Q|B|C]]|D|@]|E|$]]|$1|H|3|I|5|6|7|1R|8|@$9|1S|A|1T|B|C]|$9|1U|A|1V|B|C]|$9|1W|A|1X|B|C]|$9|1Y|A|1Z|B|C]|$9|20|A|21|B|C]|$9|22|A|23|B|C]]|D|@]|E|$]]|$1|J|3|K|5|6|7|24|8|@$9|25|A|26|B|C]|$9|27|A|28|B|C]]|D|@]|E|$]]|$1|L|3|M|5|6|7|29|8|@$9|2A|A|2B|B|C]|$9|2C|A|2D|B|C]|$9|2E|A|2F|B|C]]|D|@]|E|$]]|$1|N|3|O|5|6|7|2G|8|@]|D|@]|E|$]]|$1|P|3|Q|5|R|7|2H|8|@]|D|@]|E|$S|T]]|$1|U|3|-4|5|6|7|2I|8|@]|D|@]|E|$]]]|V|$W|$5|X|Y|Z|E|$10|11]]]]

If you look at the <a href="https://docs.python.org/2/library/exceptions.html" rel="noreferrer">documentation for the built-in errors</a>, you'll see that most <code>Exception</code> classes assign their first argument as a <code>message</code> attribute. Not all of them do though.

Notably,<code>EnvironmentError</code> (with subclasses <code>IOError</code> and <code>OSError</code>) has a first argument of <code>errno</code>, second of <code>strerror</code>. There is no <code>message</code>... <code>strerror</code> is roughly analogous to what would normally be a <code>message</code>.

More generally, subclasses of <code>Exception</code> can do whatever they want. They may or may not have a <code>message</code> attribute. Future built-in <code>Exception</code>s may not have a <code>message</code> attribute. Any <code>Exception</code> subclass imported from third-party libraries or user code may not have a <code>message</code> attribute.

I think the proper way of handling this is to identify the specific <code>Exception</code> subclasses you want to catch, and then catch only those instead of everything with an <code>except Exception</code>, then utilize whatever attributes that specific subclass defines however you want.

If you must <code>print</code> something, I think that printing the caught <code>Exception</code> itself is most likely to do what you want, whether it has a <code>message</code> attribute or not.

You could also check for the message attribute if you wanted, like this, but I wouldn't really suggest it as it just seems messy:

<pre><code>try:
 pass
except Exception as e:
 # Just print(e) is cleaner and more likely what you want,
 # but if you insist on printing message specifically whenever possible...
 if hasattr(e, 'message'):
 print(e.message)
 else:
 print(e)
</code></pre>

blocks|key|4459970|text|我也有同样的问题。我认为最好的解决方案是使用log.exception，它会自动打印堆栈跟踪和错误消息，例如：|type|unstyled|depth|inlineStyleRanges|entityRanges|data|4459971|try:
++++pass
++++log.info('Success')
except:
++++log.exception('Failed')|code-block|syntax|javascript|4459972|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

I had the same problem. I think the best solution is to use log.exception, which will automatically print out stack trace and error message, such as:

<pre><code>try:
 pass
 log.info('Success')
except:
 log.exception('Failed')
</code></pre>

blocks|key|4459951|text|我也有同样的问题。深入研究这一点，我发现exception类有一个args属性，该属性捕获用于创建异常的参数。如果您将except捕获的异常缩小到一个子集，您应该能够确定它们是如何构造的，从而确定包含该消息的参数。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|4459952|try:
+++#+do+something+that+may+raise+an+AuthException
except+AuthException+as+ex:
+++if+ex.args[0]+==+"Authentication+Timeout.":
++++++#+handle+timeout
+++else:
++++++#+generic+handling|code-block|syntax|javascript|4459953|entityMap^0|X|4|0|0^^$0|@$1|2|3|4|5|6|7|M|8|@$9|N|A|O|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|P|8|@]|D|@]|E|$I|J]]|$1|K|3|-4|5|6|7|Q|8|@]|D|@]|E|$]]]|L|$]]

I too had the same problem. Digging into this I found that the Exception class has an <code>args</code> attribute, which captures the arguments that were used to create the exception. If you narrow the exceptions that except will catch to a subset, you should be able to determine how they were constructed, and thus which argument contains the message.
<pre><code>try:
 # do something that may raise an AuthException
except AuthException as ex:
 if ex.args[0] == &quot;Authentication Timeout.&quot;:
 # handle timeout
 else:
 # generic handling
</code></pre>

blocks|key|4460037|text|from+traceback+import+format_exc


try:
++++fault+=+10/0
except+ZeroDivision:
++++print(format_exc())|type|code-block|depth|inlineStyleRanges|entityRanges|data|syntax|javascript|4460038|另一种可能是使用回溯模块中的format_exc()方法。|unstyled|4460039|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$B|C]]|$1|D|3|E|5|F|7|J|8|@]|9|@]|A|$]]|$1|G|3|-4|5|F|7|K|8|@]|9|@]|A|$]]]|H|$]]

<pre><code>from traceback import format_exc


try:
 fault = 10/0
except ZeroDivision:
 print(format_exc())
</code></pre>
Another possibility is to use the format_exc() method from the traceback module.

What is the best way to get exceptions' messages from components of standard library in Python?

I noticed that in some cases you can get it via <code>message</code> field like this:

<pre><code>try:
 pass
except Exception as ex:
 print(ex.message)
</code></pre>

but in some cases (for example, in case of socket errors) you have to do something like this:

<pre><code>try:
 pass
except socket.error as ex:
 print(ex)
</code></pre>

I wondered is there any standard way to cover most of these situations?

How to get exception message in Python properly

Python

从Python标准库的组件中获取异常消息的最佳方式是什么？我注意到，在某些情况下，您可以通过message字段获取它，如下所示：try:  passexcept Exception as ex:  print(ex.message)但在某些情况下(例如，在套接字错误的情况下)，您必须这样做：try:  passexce...

问如何在Python中正确获取异常消息
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