I'm relatively new to NumPy/SciPy and IPython.
To execute a python script in the python interactive mode, we may use the following commands.
>>> import os
>>> os.system('executable.py')
Then the print outputs can be seen from the python prompt.
But the same idea doesn't work with IPython notebook.
In [64]:
import os
os.system('executable.py')
Out[64]:
0
In this case, I cannot see any print outputs. The notebook only tells weather execution was successful or not. Are there any ways to see the outputs when I use IPython notebook?
Use the magic function %run:
%run executable.py
This properly redirects stdout to the browser and you will see the output from the program in the notebook.
It gives you both, the typical features of running from command line plus Python tracebacks if there is exception.
Parameters after the filename are passed as command-line arguments to
the program (put in sys.argv). Then, control returns to IPython's
prompt.
This is similar to running at a system prompt python file args,
but with the advantage of giving you IPython's tracebacks, and of
loading all variables into your interactive namespace for further use
(unless -p is used, see below).
The option -t times your script. With -d it runs in the debugger pdb. More nice options to explore.
Related
(Note: I have plenty of python and unix shell experience, but fairly new to ipython -- using 7.5)
I'm trying to replicate a UNIX shell function that I use all the time, so that it works in the ipython shell.
The requirement is that I want to type something like to myproj, and then have ipython process the resulting text by doing a cd to the directory that comes back from to. (This is a quick-directory-change utility I use in unix)
The way it works in unix is that a shell function invokes an external command, that command prints its result to stdout, and the shell function then invokes the internal cd to the target dir.
I've been trying to wrap my head around %magic and macros and aliases in ipython, but so far I don't see how to get this done. Any ideas?
I am writing my script interactively with IPython. This is what I currently do:
write a chunk of code,
run in ipython with "run -i file_name.py".
make changes and repeat 2 until I think it is OK .
comment out the entire previous chunk.
write new chunk of code that is based on the previous one.
go back to step 2.
......
Is there more efficient way? Can I start a script from a specific line while using all the variables in current namespace?
Use ipdb ("pip install ipdb" on the command line to install it).
Suppose you want to run script "foo.py" from line 18 to 23.
You'll want to start like this:
ipdb foo.py
Now, let's jump to line 18 (i.e., ignore all the lines before the 18th):
ipdb> j 18
Next, we set a breakpoint at line 23 (we don't want to go further):
ipdb> b 23
Finally, let's execute:
ipdb> c
Job done :)
I'd personally also use the ipython notebook, but you call also use you favorite text editor and always copy out the chunk of code you want to run and use the magic command %paste to run that chunk in the ipython shell. It will take care of indentation for you.
Use the magic of %edit stuff.py (first use) and %ed -p (after the first use) and it will invoke your $EDITOR from inside of ipython. Upon exiting from the editor ipython will run the script (unless you called %ed -x). That is by far the fastest way I found to work in CLI-ipython. The notebooks are nice, but I like having a real editor for code.
(Based on lev's answer)
From the interactive shell:
%run -i -d foo.py
should then enter the debugger, and proceed with:
j <line_number>
c
etc.
EDIT: unfortunately, this seems to sort of break ipython's magic %debug command.
An IPython Notebook allows you to interactively run scripts line by line. It comes with IPython, just run:
ipython notebook
from the terminal to launch it. Its a web interface to IPython, where you can save the notebooks to *.py files by clicking save as in the settings.
Here's some more info from this video.
For something fast as well as flexible use http://qtconsole.readthedocs.io/en/stable/
It is similar to the Jupyter notebook based on your browsers (as pointed out by #agonti and #magellan88, but presumably much faster. It also has emacs style keybindings.
I use ipdb, ipython, comupled with tmux and vim and get almost IDE like features and much faster.
Below lines when i put them in test.py and runs it, gives me error but runs fine when i run them from command line.
pyvar = 'Hello world'
!echo "A python variable: {pyvar}"
jitu#jitu-PC:~/ipython/python$ ipython test.py
File "/home/jitu/ipython/python/test.py", line 2
!echo "A python variable: {pyvar}"
^
SyntaxError: invalid syntax
Any idea why it is not working ?
.py file are python script, they are supposed to be pure python, IPython will not try to do some "magic" on it. You should rename your script to .ipy if you want to use the syntactic sugar IPython offers on top of pure python syntax.
Note that all IPython syntactic sugar can be transformed into pure python (cf %hist vs %hist -t) that will be valid python syntax, but still need to have access to an IPython instance.
I want to run IPython from the command line. However, I get a syntax error on the first line, importing pylab with the magic function %pylab is giving a syntax error on the %. The command I am using is simply ipython -i script.py.
Any ideas how to solve this?
You need to name your file script.ipy. When it ends in .ipy it can contain ipython syntax.
From ipython --help:
Usage
ipython [subcommand] [options] [files]
If invoked with no options, it executes all the files listed in sequence
and exits, use -i to enter interactive mode after running the files. Files
ending in .py will be treated as normal Python, but files ending in .ipy
can contain special IPython syntax (magic commands, shell expansions, etc.)
Does anyone know if it is possible to run an IPython/Jupyter notebook non-interactively from the command line and have the resulting .ipynb file saved with the results of the run. If it isn't already possible, how hard would it be to implement with phantomJS, something to turn the kernel on and off, and something to turn the web server on and off?
To be more specific, let's assume I already have a notebook original.ipynb and I want to rerun all cells in that notebook and save the results in a new notebook new.ipynb, but do this with one single command on the command line without requiring interaction either in the browser or to close the kernel or web server, and assuming no kernel or web server is already running.
example command:
$ ipython notebook run original.ipynb --output=new.ipynb
Yes it is possible, and easy, it will (mostly) be in IPython core for 2.0, I would suggest looking at those examples for now.
[edit]
$ jupyter nbconvert --to notebook --execute original.ipynb --output=new.ipynb
It is now in Jupyter NbConvert. NbConvert comes with a bunch of Preprocessors that are disabled by default, two of them (ClearOutputPreprocessor and ExecutePreprocessor) are of interest. You can either enabled them in your (local|global) config file(s) via c.<PreprocessorName>.enabled=True (Uppercase that's python), or on the command line with --ExecutePreprocessor.enabled=True keep the rest of the command as usual.
The --ExecutePreprocessor.enabled=True has convenient --execute alias that can be used on recent version of NbConvert. It can be combine with --inplace if desired
For example, convert to html after running the notebook headless :
$ jupyter nbconvert --to=html --execute RunMe.ipynb
converting to PDF after stripping outputs
$ ipython nbconvert --to=pdf --ClearOutputPreprocessor.enabled=True RunMe.ipynb
This (of course) does work with non-python kernels by spawning a <insert-your-language-here> kernel, if you set --profile=<your fav profile>. The conversion can be really long as it needs to rerun the notebook. You can do notebook to notebook conversion with the --to=notebook option.
There are various other options (timeout, allow errors, ...) that might need to be set/unset depending on use case. See documentation and of course jupyter nbconvert --help, --help-all, or nbconvert online documentation for more information.
Until this functionality becomes part of the core, I put together a little command-line app that does just what you want. It's called runipy and you can install it with pip install runipy. The source and readme are on github.
Run and replace original .ipynb file:
jupyter nbconvert --ExecutePreprocessor.timeout=-1 --to notebook --inplace --execute original.ipynb
To cover some features such as parallel workers, input parameters, e-mail sending or S3 input/output... you can install jupyter-runner
pip install jupyter-runner
Readme on github: https://github.com/omar-masmoudi/jupyter-runner
One more way is to use papermill, it has Command Line Interface
Usage example: (you need to specify output path for execution results to be stored)
papermill your_notebook.ipynb logs/yourlog.out.ipynb
You also can specify required params if you wish with -p flag for each param:
papermill your_notebook.ipynb logs/yourlog.out.ipynb -p env "prod" -p tests "e2e"
one more related to papermill reply - https://stackoverflow.com/a/55458141/2957102
You can just run the iPython-Notebook-server via command line:
ipython notebook --pylab inline
This will start the server in non-interactive mode and all output is printed below the code. You can then save the .ipynb-File which includes Code & Output.