Convert IPython notebook to zds markdown

cipyn.py

#!/usr/bin/env python3

import json
import sys
import base64

__N_IMG = 0


def handle_heading(c, write):
    write("#" * c["level"] + " " + "".join(c["source"]) + "\n")


def handle_markdown(c, write):
    write("".join(c["source"]))


def handle_code(c, write):
    write("```{}\n".format(c["language"]))
    write("".join(c["input"]))
    write("\n```\n")

    lo = c["outputs"]
    if len(lo):
        outp = lo[0]

        if outp["output_type"] == "display_data" and "png" in outp:
            global __N_IMG
            png_data = base64.b64decode(outp["png"])
            ifn = "Image{}.png".format(__N_IMG)
            with open(ifn, "wb") as f:
                f.write(png_data)
            write("\n**Sortie:**\n\n")
            write("![]({})\n".format(ifn))
            __N_IMG += 1
        elif "text" in outp:
            write("\n**Sortie:**   \n`")
            write("```text\n")
            write("".join(outp["text"]))
            write("\n```\n")
        else:
            print("Output type '{}' not supported".format(outp["output_type"]))


def conv_ipython_notebook(filename_to_conv, output_filename):

    with open(filename_to_conv) as fjson:
        odc_ipy = json.load(fjson)

    vmajor = odc_ipy["nbformat"]
    vminor = odc_ipy["nbformat_minor"]
    if vmajor != 3 or vminor != 0:
        print("Warning : this source file is from iPython Notebook {}.{}. This script is designed to support iPython Notebbok {}.{}.".format(vmajor, vminor, 3, 0))

    data = []
    write = lambda tx : data.append(tx)

    hh = {"markdown": handle_markdown,
          "code":     handle_code,
          "heading":  handle_heading,
          }

    ws =  odc_ipy["worksheets"][0]
    for c in ws["cells"]:
        hh[c["cell_type"]](c, write)
        write("\n\n")

    output = "".join(data)
    with open(output_filename, "w") as f:
        f.write(output)

if __name__ == "__main__":
    conv_ipython_notebook(sys.argv[1], sys.argv[2])