def nb2subnb(filename, *, cell_type='markdown', 
             single_nb=False, keep_cells=[], keep_texts=[]):
    r"""
    (nb2subnb) splits out typed cells of jupyter 
    notebooks into n sub-notebooks.

    examples:

       # split into n markdown cell notebooks
       nb2subnb(r'C:\temp\UsingJodliterate.ipynb')

       # split into n code cell notebooks
       nb2subnb(r'C:\temp\UsingJodliterate.ipynb', 
           cell_type='code')

       # all markdown cells in single notebook
       nb2subnb(r'C:\temp\UsingJodliterate.ipynb', 
           single_nb='True')

       # code cells with numbers in range as single notebook
       nb2subnb(r'C:\temp\UsingJodliterate.ipynb', 
           cell_type='code', single_nb='True', 
           keep_cells=list(range(10)))

       # markdown cells with strings 'Bhagavad' or 'github' 
       nb2subnb(r'C:\temp\UsingJodliterate.ipynb', 
           single_nb='True',
           keep_texts=['Bhagavad','github'])

       # all code cells in range with string 'pacman' 
       nb2subnb(r'C:\temp\UsingJodliterate.ipynb', 
           cell_type='code',
           keep_texts=['pacman'], keep_cells=list(range(30)))

    """
    with open(filename) as in_file:
        nb_data = json.load(in_file)

    # notebook file name without extension/path
    nbname = os.path.basename(os.path.splitext(filename)[0])

    nb_cells, one_cell, nb_files = dict(), list(), list()

    for cnt, cell in enumerate(nb_data['cells']):
        if nb_data['cells'][cnt]['cell_type'] == cell_type:

            if not single_nb:
                # single cell notebooks
                nb_cells, one_cell = dict(), list()
                if 0 == len(keep_cells) or cnt in keep_cells:
                    if text_in_source(cell, keep_texts):
                        one_cell.append(cell)
                        nb_cells["cells"] = one_cell
                        nb_cells = insert_nb_metadata(
                            nb_data, nb_cells)
                        nb_out_file = NB_DIRECTORY + \
                            nbname + '-' + cell_type + \
                            '-' + str(cnt) + '.ipynb'
                        nb_files.append(nb_out_file)
                        with open(nb_out_file, 'w') as out_file:
                            json.dump(nb_cells, out_file,
                                      ensure_ascii=False)
            elif single_nb:
                # single notebook with only (cell_type) cells
                if 0 == len(keep_cells) or cnt in keep_cells:
                    if text_in_source(cell, keep_texts):
                        one_cell.append(cell)
                        nb_cells["cells"] = one_cell

    if single_nb:
        nb_out_file = NB_DIRECTORY + \
            nbname + '-' + cell_type + '-only.ipynb'
        nb_files.append(nb_out_file)
        nb_cells = insert_nb_metadata(nb_data, nb_cells)
        with open(nb_out_file, 'w') as out_file:
            json.dump(nb_cells, out_file, 
                      ensure_ascii=False)

    # list of generated sub-notebooks
    return nb_files

# append nb2* script directory to system path
import sys
sys.path.append(r'C:\temp\nb2wp')

# notebook file
nb_file = r'C:\temp\nb2wp\UsingJodliterate.ipynb'

nb2subnb_opts = {
    'single_nb': False,
    'cell_type': 'code',
    'keep_cells': [2, 8, 21],
    'keep_texts': []
}

import nb2wput as nbu

# split notebook into selected parts and convert to HTML 
nbu.nb2wpblk(nb_file, nb2subnb_parms=nb2subnb_opts)