Converting to (not from) ipython Notebook format

Question

IPython Notebook comes with nbconvert, which can export notebooks to other formats. But how do I convert text in the opposite direction? I ask because I already ha

Answer 1

Given the example by Volodimir Kopey, I put together a bare-bones script to convert a .py obtained by exporting from a .ipynb back into a V4 .ipynb.

I hacked this script together when I edited (in a proper IDE) a .py I had exported from a Notebook and I wanted to go back to Notebook to run it cell by cell.

The script handles only code cells. The exported .py does not contain much else, anyway.

import nbformat
from nbformat.v4 import new_code_cell,new_notebook

import codecs

sourceFile = "changeMe.py"     # <<<< change
destFile = "changeMe.ipynb"    # <<<< change


def parsePy(fn):
    """ Generator that parses a .py file exported from a IPython notebook and
extracts code cells (whatever is between occurrences of "In[*]:").
Returns a string containing one or more lines
"""
    with open(fn,"r") as f:
        lines = []
        for l in f:
            l1 = l.strip()
            if l1.startswith('# In[') and l1.endswith(']:') and lines:
                yield "".join(lines)
                lines = []
                continue
            lines.append(l)
        if lines:
            yield "".join(lines)

# Create the code cells by parsing the file in input
cells = []
for c in parsePy(sourceFile):
    cells.append(new_code_cell(source=c))

# This creates a V4 Notebook with the code cells extracted above
nb0 = new_notebook(cells=cells,
                   metadata={'language': 'python',})

with codecs.open(destFile, encoding='utf-8', mode='w') as f:
    nbformat.write(nb0, f, 4)

No guarantees, but it worked for me