jupyter: how to stop execution on errors?

2024/11/15 0:41:02

The common way to defensively abort execution in python is to simply do something like:

if something_went_wrong:print("Error message: goodbye cruel world")exit(1)

However, this is not good practice when using jupyter notebook, as this seems to abort the kernel entirely, which is not always wanted. Is there are proper/better way in jupyter, besides hack-y infinite loops?

Answer

No, exit() is not the way to abort Python execution usually. exit() is meant to stop the interpreter immediately with a status code.

Usually, you will write a script like that:

 if __name__ == '__main__':sys.exit(main())

Try not to put sys.exit() in the middle of your code — it is bad practice, and you might end up with non closed filehandle or locked resources.

To do what you want, just raise an exception of the correct type. If it propagate to the eval loop, IPython will stop the notebook execution.

Also, it will give you useful error messages and a stack trace.

if type(age) is not int:raise TypeError("Age must be an integer")
elif age < 0:raise ValueError("Sorry you can't be born in the future")
else :...

You can even inspect the stack post-mortem with %debug to see what went wrong where, but that is another subject.

https://en.xdnf.cn/q/72152.html

Related Q&A

Python 2.7 on Google App Engine, cannot use lxml.etree

Ive been trying to use html5lib with lxml on python 2.7 in google app engine. But when I run the following code, it gives me an error saying "NameError: global name etree is not defined". Is …

Pandas split name column into first and last name if contains one space

Lets say I have a pandas DataFrame containing names like so:name_df = pd.DataFrame({name:[Jack Fine,Kim Q. Danger,Jane Smith, Juan de la Cruz]})name 0 Jack Fine 1 Kim Q. Danger 2 Jane Smith 3 J…

Docker. No such file or directory

I have some files which I want to move them to a docker container. But at the end docker cant find a file..The folder with the files on local machine are at /home/katalonne/flask4File Structure if it m…

How to recover original values after a model predict in keras?

This is a more conceptual question, but I have to confess I have been dealing with it for a while. Suppose you want to train a neural network (NN), using for instance keras. As it is recommended you pe…

Find closest line to each point on big dataset, possibly using shapely and rtree

I have a simplified map of a city that has streets in it as linestrings and addresses as points. I need to find closest path from each point to any street line. I have a working script that does this, …

Reading pretty print json files in Apache Spark

I have a lot of json files in my S3 bucket and I want to be able to read them and query those files. The problem is they are pretty printed. One json file has just one massive dictionary but its not in…

Visualize TFLite graph and get intermediate values of a particular node?

I was wondering if there is a way to know the list of inputs and outputs for a particular node in tflite? I know that I can get input/outputs details, but this does not allow me to reconstruct the com…

Why do I get a pymongo.cursor.Cursor when trying to query my mongodb db via pymongo?

I have consumed a bunch of tweets in a mongodb database. I would like to query these tweets using pymongo. For example, I would like to query for screen_name. However, when I try to do this, python doe…

using dropbox as a server for my django app

I dont know if at all i make any sense, but this popped up in my mind. Can we use the 2gb free hosting of dropbox to put our django app over there and do some hacks to run our app?

Proper overloading of json encoding and decoding with Flask

I am trying to add some overloading to the Flask JSON encoder/decoder to add datetime encoding/decoding but only succeeded through a hack.from flask import Flask, flash, url_for, redirect, render_templ…