How do I convert a IPython Notebook into a Python

问题:

I'm looking at using the *.ipynb files as the source of truth and programmatically 'compiling' them into .py files for scheduled jobs/tasks.

The only way I understand to do this is via the GUI. Is there a way to do it via command line?

回答1:

If you don't want to output a Python script every time you save, or you don't want to restart the IPython kernel:

On the command line, you can use nbconvert:

$ jupyter nbconvert --to script [YOUR_NOTEBOOK].ipynb

As a bit of a hack, you can even call the above command in an IPython notebook by pre-pending ! (used for any command line argument). Inside a notebook:

!jupyter nbconvert --to script config_template.ipynb

Before --to script was added, the option was --to python or --to=python, but it was renamed in the move toward a language-agnostic notebook system.

回答2:

If you want to convert all *.ipynb files from current directory to python script, you can run the command like this:

jupyter nbconvert --to script *.ipynb

回答3:

Here is a quick and dirty way to extract the code from V3 or V4 ipynb without using ipython. It does not check cell types, etc.

import sys,json

f = open(sys.argv[1], 'r') #input.ipynb
j = json.load(f)
of = open(sys.argv[2], 'w') #output.py
if j["nbformat"] >=4:
        for i,cell in enumerate(j["cells"]):
                of.write("#cell "+str(i)+"\n")
                for line in cell["source"]:
                        of.write(line)
                of.write('\n\n')
else:
        for i,cell in enumerate(j["worksheets"][0]["cells"]):
                of.write("#cell "+str(i)+"\n")
                for line in cell["input"]:
                        of.write(line)
                of.write('\n\n')

of.close()

回答4:

Following the previous example but with the new nbformat lib version :

import nbformat
from nbconvert import PythonExporter

def convertNotebook(notebookPath, modulePath):

  with open(notebookPath) as fh:
    nb = nbformat.reads(fh.read(), nbformat.NO_CONVERT)

  exporter = PythonExporter()
  source, meta = exporter.from_notebook_node(nb)

  with open(modulePath, 'w+') as fh:
    fh.writelines(source.encode('utf-8'))

回答5:

You can do this from the IPython API.

from IPython.nbformat import current as nbformat
from IPython.nbconvert import PythonExporter

filepath = 'path/to/my_notebook.ipynb'
export_path = 'path/to/my_notebook.py'

with open(filepath) as fh:
    nb = nbformat.reads_json(fh.read())

exporter = PythonExporter()

# source is a tuple of python source code
# meta contains metadata
source, meta = exporter.from_notebook_node(nb)

with open(export_path, 'w+') as fh:
    fh.writelines(source)

回答6:

@Spawnrider's last line of code,

fh.writelines(source.encode('utf-8'))

gives 'TypeError: write() argument must be str, not int'

fh.writelines(source) 

works though.

回答7:

For converting all *.ipynb format files in current directory to python scripts recursively:

for i in *.ipynb **/*.ipynb; do 
    echo "$i"
    jupyter nbconvert  "$i" "$i"
done

回答8:

I had this problem and tried to find the solution online. Though I found some solutions, they still have some problems, e.g., the annoying Untitled.txt auto-creation when you start a new notebook from the dashboard.

So eventually I wrote my own solution:

import io
import os
import re
from nbconvert.exporters.script import ScriptExporter
from notebook.utils import to_api_path


def script_post_save(model, os_path, contents_manager, **kwargs):
    """Save a copy of notebook to the corresponding language source script.

    For example, when you save a `foo.ipynb` file, a corresponding `foo.py`
    python script will also be saved in the same directory.

    However, existing config files I found online (including the one written in
    the official documentation), will also create an `Untitile.txt` file when
    you create a new notebook, even if you have not pressed the "save" button.
    This is annoying because we usually will rename the notebook with a more
    meaningful name later, and now we have to rename the generated script file,
    too!

    Therefore we make a change here to filter out the newly created notebooks
    by checking their names. For a notebook which has not been given a name,
    i.e., its name is `Untitled.*`, the corresponding source script will not be
    saved. Note that the behavior also applies even if you manually save an
    "Untitled" notebook. The rationale is that we usually do not want to save
    scripts with the useless "Untitled" names.
    """
    # only process for notebooks
    if model["type"] != "notebook":
        return

    script_exporter = ScriptExporter(parent=contents_manager)
    base, __ = os.path.splitext(os_path)

    # do nothing if the notebook name ends with `Untitled[0-9]*`
    regex = re.compile(r"Untitled[0-9]*$")
    if regex.search(base):
        return

    script, resources = script_exporter.from_filename(os_path)
    script_fname = base + resources.get('output_extension', '.txt')

    log = contents_manager.log
    log.info("Saving script at /%s",
             to_api_path(script_fname, contents_manager.root_dir))

    with io.open(script_fname, "w", encoding="utf-8") as f:
        f.write(script)

c.FileContentsManager.post_save_hook = script_post_save

To use this script, you can add it to ~/.jupyter/jupyter_notebook_config.py :)

Note that you may need to restart the jupyter notebook / lab for it to work.