ipython notebook needs the option to output .ipy script without encoding problems when run

[peterswanson]

Currently, the '--script' option in ipython notebook outputs a .py file, but this won't work if any cell magic commands are run inside of it. I made a script to change the extension to .ipy and delete the encoding first line (that causes a problem for ipython, but it would be nice if ipython notebook could do this itself.

[takluyver]

We don't particularly want to encourage the use of .ipy scripts, I think - they're there for convenience, but it's better to work with regular .py files. But we should do something sensible in this case - perhaps saving the transformed code.

[peterswanson]

Is that because magic functions can be customized within individual profiles that won't be compatible on other users systems and you all don't want code that won't work on anyone else's system to propagate the web?
It is very convenient as a user to save your use of magic functions and bash commands to a script to run over and over. Is there a better way to use the full ipython functionality in a script besides this?

[minrk]

Writing out the pure Python doesn't mean it doesn't use IPython, it just means it doesn't use IPython's syntax.
For instance, in the transformed history, %timeit time.sleep(0) is actually get_ipython().magic(u'timeit time.sleep(0)'). This is what we should write to a .py file, not the IPython syntax, which is not valid Python.

[peterswanson]

Ok, that makes sense :)
So, when I set my ipython notebook to create a .py script (through the --script option), why doesn't ipython notebook write get_ipython().magic(u'timeit time.sleep(0)')? Instead, I get a script that would have: %timeit time.sleep(0). This .py file can't be run by python, and ipython won't run it as a magic command unless it has the .ipy extension. This is why I was trying to rename it and wishing that ipython notebook would do this for me.
Am I missing something?

[minrk]

It's just a bug - we should either be writing a .ipy file with IPython syntax, or a .py file with pure Python. Right now we write IPython syntax to a .py file, which is plain wrong.

[peterswanson]

ok, is that a bug on my system only and it works on other's systems? Or is this a problem with ipython in general?

[minrk]

IPython in general - the python exporter doesn't transform IPython syntax at all, but it probably should transform it into Python.

[peterswanson]

Ok, cool. Well, I know theres probably lots of things to do on the list, so
no pressure. Thanks for all the hard work :)

On Sat, Mar 30, 2013 at 8:05 PM, Min RK notifications@github.com wrote:

IPython in general - the python exporter doesn't transform IPython syntax
at all, but it probably should transform it into Python.

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Reply to this email directly or view it on GitHubhttps://github.com//issues/3111#issuecomment-15684182
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[git42]

docs/source/whatsnew/pr/incompat-contents-service.rst
The --script hook for saving notebooks to Python scripts is removed, use "ipython nbconvert --to python {notebook}" instead.

What about having a notebook switch --nbconvert-to {type} to automatically save notebooks to other formats?

[minrk]

If anything, we should have a generic post_save hook. I don't think special-casing this particular behavior makes sense.

[mforbes]

Please implement a post_save hook soon, especially since --script support has been removed. Not all version control systems have smudge filters that can work as a universal replacement yet.

[jankatins]

post save hook (and discussion about such a feature): #3312