converter.py

import io, sys
from IPython.nbformat import current
from IPython.config import Config
from IPython.nbconvert import HTMLExporter



def loadNotebook(filename):
    """Load notebook from file."""
    with io.open(filename, 'r', encoding='utf-8') as f:
        nb = current.read(f, 'json')
    return nb


def split_into_units(nb):
    """Split notebook into units for edX exporter."""
    indexes = []
    cells = nb.worksheets[0].cells
    for (i, cell) in enumerate(cells):
        if cell.cell_type == 'heading' and cell.level == 1:
            indexes.append(i)

    separated_cells = [cells[i:j] for i, j in zip(indexes, indexes[1:]+[None])]

    worksheets = map(lambda cells: current.new_worksheet(name=cells[0].source, cells=cells), separated_cells)
    units = map(lambda worksheet: current.new_notebook(name=worksheet.name, worksheets=[worksheet]), worksheets)
    return units


def export_units(units, folder):
    """Export units into separate html files and save into folder."""
    output_files = []
    exportHtml = HTMLExporter(config=Config({'HTMLExporter':{'default_template':'basic'}}))
    for unit in units:
        (body, resources) = exportHtml.from_notebook_node(unit)
        name = folder + '/' + unit.metadata.name + '.html'
        name = list(name)
        for (i,c) in enumerate(name):
            if c == ' ': name[i] = '_'
        name = "".join(name)
        output_files.append(name)
        with io.open(name, 'w', encoding='utf-8') as f:
            f.write(body)
    return output_files



def converter(notebook_file, output_folder):
    """
    Export given notebook into separated units.

    Input
    -----
    notebook_file : str
        A relative path to notebook file.

    output_folder : str
        A relative path to a target folder. All created units will
        be saved there. Folder must exist.
    """
    nb = loadNotebook(notebook_file)
    units = split_into_units(nb)
    names = export_units(units, output_folder)

    return names