I would like to handle the following Exception from py_vollib/py_lets_be_rational in specific way. Tried this without success: what am I doing wrong? any help would be appreciated. Answer Looking at the implementation, you’re missing the period at the end of the sentence: I don’t see the point in …
Tag: exception
What is the simplest way to retry a Django view upon an exception being raised?
I want to rerun a Django view function if a certain exception is raised (in my case a serialization error in the underlying database). I want it to run with exactly the same parameters, including the same request object – as if the client had re-requested the URL. There are many database queries in the …
How to get python default exception message in exception handling
When I handle an exception in python It prints I expect it to print Is there a way to retrieve the default error message ? Answer Instead of this: do this: or just this:
Python “raise from” usage
What’s the difference between raise and raise from in Python? which yields and which yields Answer The difference is that when you use from, the __cause__ attribute is set and the message states that the exception was directly caused by. If you omit the from then no __cause__ is set, but the __context__…
Multiple try codes in one block
I have a problem with my code in the try block. To make it easy this is my code: Is something like this possible? Answer You’ll have to make this separate try blocks: This assumes you want to run code c only if code b failed. If you need to run code c regardless, you need to put the try
Python: Catching specific exception
I want to catch a specific ValueError, not just any ValueError. I tried something like this: But it raises a SyntaxError: can’t assign to literal. Then I tried: But it raises the exception, even if it is the one I want to avoid. Answer in except ValueError,e, e is an instance of the exception, not a str…
Handling a timeout error in Python sockets
I am trying to figure out how to use the try and except to handle a socket timeout. The way I added the socket module was to import everything, but how do I handle exceptions? In the documentation it says you can use socket.timeouterror, but that doesn’t work for me. Also, how would I write the try exce…
Why do we need the “finally” clause in Python?
I am not sure why we need finally in try…except…finally statements. In my opinion, this code block is the same with this one using finally: Am I missing something? Answer It makes a difference if you return early: Compare to this: Other situations that can cause differences: If an exception is thr…
Extract traceback info from an exception object
Given an Exception object (of unknown origin) is there way to obtain its traceback? I have code like this: How can I extract the traceback from the Exception object once I have it? Answer The answer to this question depends on the version of Python you’re using. In Python 3 It’s simple: exceptions…
“except” statement with same exception class as parameter twice
In Python, how can I use except block with same exception name twice in try/except statements without need to wrap code into one more try/except block? Simple example (here each call of pages.get may raise the exception): For now, in my Django app I do handling like this (but I don’t want “extra&#…