I have been using this for more than a year and I have just realized I don't have any blog entry about it?

Notebook2script

As you may know, the full fastai v2 has been written in notebooks.

This is quite impressive these notebooks are documentation + code, and fastai libraries are built from these notebooks.

I have been using one of the first version of Jeremy Howard's process, I am quite sure there have been many improvment since then.

Here is the source code for notebook2script.py download

import json,fire,re
from pathlib import Path
import io

def is_export(cell):
    if cell['cell_type'] != 'code': return False
    src = cell['source']
    if len(src) == 0 or len(src[0]) < 7: return False
    #import pdb; pdb.set_trace()
    return re.match(r'^\s*#\s*export\s*$', src[0], re.IGNORECASE) is not None

def getSortedFiles(allFiles, upTo=None):
    '''Returns all the notebok files sorted by name.
       allFiles = True : returns all files
                = '*_*.ipynb' : returns this pattern
       upTo = None : no upper limit
            = filter : returns all files up to 'filter' included
       The sorting optioj is important to ensure that the notebok are executed in correct order.
    '''
    import glob
    ret = []
    if (allFiles==True): ret = glob.glob('*.ipynb') # Checks both that is bool type and that is True
    if (isinstance(allFiles,str)): ret = glob.glob(allFiles)
    if 0==len(ret): 
        print('WARNING: No files found')
        return ret
    if upTo is not None: ret = [f for f in ret if str(f)<=str(upTo)]
    return sorted(ret)

def notebook2script(fname=None, allFiles=None, upTo=None, fnameout=None):
    '''Finds cells starting with `#export` and puts them into a new module
       + allFiles: convert all files in the folder
       + upTo: convert files up to specified one included
       
       ES: 
       notebook2script --allFiles=True   # Parse all files
       notebook2script --allFiles=nb*   # Parse all files starting with nb*
       notebook2script --upTo=10   # Parse all files with (name<='10')
       notebook2script --allFiles=*_*.ipynb --upTo=10   # Parse all files with an '_' and (name<='10')
       notebook2script --fnameout='test_25.py'

    '''
    # initial checks
    if (allFiles is None) and (upTo is not None): allFiles=True # Enable allFiles if upTo is present
    if (fname is None) and (not allFiles): print('Should provide a file name')
    if not allFiles: notebook2scriptSingle(fname, fnameout)
    else:
        print('Begin...')
        [notebook2scriptSingle(f, fnameout) for f in getSortedFiles(allFiles,upTo)]
        print('...End')
        
        
def notebook2scriptSingle(fname, *fname_out):
    "Finds cells starting with `#export` and puts them into a new module"
    fname = Path(fname)
    if (fname_out[0]==None): 
        fname_out = f'nb_{fname.stem.split("_")[0]}.py' 
    else: fname_out = fname_out[0]
    main_dic = json.load(open(fname,'r',encoding="utf-8"))
    code_cells = [c for c in main_dic['cells'] if is_export(c)]
    module = f'''
#################################################
### THIS FILE WAS AUTOGENERATED! DO NOT EDIT! ###
#################################################
# file to edit: {fname.name}

'''
    for cell in code_cells: module += ''.join(cell['source'][1:]) + '\n\n'
    # remove trailing spaces
    module = re.sub(r' +$', '', module, flags=re.MULTILINE)
    if not (fname.parent/'exp').exists(): (fname.parent/'exp').mkdir()
    output_path = fname.parent/'exp'/fname_out
    with io.open(output_path, "w", encoding="utf-8") as f:
        f.write(module[:-2])
    print(f"Converted {fname} to {output_path}")

if __name__ == '__main__': fire.Fire(notebook2script)

How to extract modules from notebooks

Mark cells to be exported in your notebook

notebook2scriptexpects a keyword at the top of each cell to be exported. This keyword is #export.

variable3 = 'Not this one'

You got the idea

Export your module `my_great_module`

#code from Jeremy Howard (fastai v2)
#!python notebook2script.py "00D059_init_and_import.ipynb"
!python notebook2script.py --fnameout="my_great_module.py"  "2021-09-29-nbdev-notebook2script.ipynb"

Converted 2021-09-29-nbdev-notebook2script.ipynb to exp/my_great_module.py

Exported module

If subfolder exp doesn't exist, it will be automatically created.

And my_great_module.py is being created as well.

Here is the content generated.

!cat exp/my_great_module.py

#################################################
### THIS FILE WAS AUTOGENERATED! DO NOT EDIT! ###
#################################################
# file to edit: 2021-09-29-nbdev-notebook2script.ipynb


variable = 'This will be exported in a module'


variable2 = 'This one as well'

Python library needed: fire

import sys
!conda install --yes --prefix {sys.prefix}  -c conda-forge fire

Collecting package metadata (current_repodata.json): done
Solving environment: done


==> WARNING: A newer version of conda exists. <==
  current version: 4.10.1
  latest version: 4.10.3

Please update conda by running

    $ conda update -n base -c defaults conda


## Package Plan ##

  environment location: /home/guillaume/anaconda3/envs/xgboost

  added / updated specs:
    - fire


The following packages will be UPDATED:

  fire                                           0.2.1-py_0 --> 0.4.0-pyh44b312d_0


Preparing transaction: done
Verifying transaction: done
Executing transaction: done

Combine with pdoc to generate documentation

#!python notebook2script.py "00D059_init_and_import.ipynb"

library_name = "dataprophet"
notebook_name = "00 - dataprophet library - dataprophet"

!python notebook2script.py --fnameout="{library_name}.py"  "{notebook_name}.ipynb"

!pdoc --html --output-dir exp/html --force "exp/{library_name}.py"

Note the {} notation which allows to use ipython variables as arguments to bash commands

Proper docstring

See in Autogenerate documentation from custom python classes