Module to import from ipython notebooks

readme.md

Module to import from ipython notebooks

Origin

This module is entirely the work of Adrian Price-Whelan, and was directly collated from his notebook http://nbviewer.ipython.org/github/adrn/ipython/blob/1.x/examples/notebooks/Importing%20Notebooks.ipynb

Usage

Place this module in a location on your python path, then add a config instruction to your .ipython/profile_default/ipython_notebook_config.py:

c.InteractiveShellApp.exec_lines = [ 'import notebook_importing' ]

You will then be able to import directly from other ipython notebooks in every notebook session.

notebook_importing.py

"""
Module directly collated from
http://nbviewer.ipython.org/github/adrn/ipython/blob/1.x/examples/notebooks/Importing%20Notebooks.ipynb
"""
import io, os, sys, types
from IPython.nbformat import current
from IPython.core.interactiveshell import InteractiveShell

def find_notebook(fullname, path=None):
    """find a notebook, given its fully qualified name and an optional path

    This turns "foo.bar" into "foo/bar.ipynb"
    and tries turning "Foo_Bar" into "Foo Bar" if Foo_Bar
    does not exist.
    """
    name = fullname.rsplit('.', 1)[-1]
    if not path:
        path = ['']
    for d in path:
        nb_path = os.path.join(d, name + ".ipynb")
        if os.path.isfile(nb_path):
            return nb_path
        # let import Notebook_Name find "Notebook Name.ipynb"
        nb_path = nb_path.replace("_", " ")
        if os.path.isfile(nb_path):
            return nb_path

class NotebookLoader(object):
    """Module Loader for IPython Notebooks"""
    def __init__(self, path=None):
        self.shell = InteractiveShell.instance()
        self.path = path

    def load_module(self, fullname):
        """import a notebook as a module"""
        path = find_notebook(fullname, self.path)

        print ("importing IPython notebook from %s" % path)

        # load the notebook object
        with io.open(path, 'r', encoding='utf-8') as f:
            nb = current.read(f, 'json')

        # create the module and add it to sys.modules
        # if name in sys.modules:
        #    return sys.modules[name]
        mod = types.ModuleType(fullname)
        mod.__file__ = path
        mod.__loader__ = self
        sys.modules[fullname] = mod

        # extra work to ensure that magics that would affect the user_ns
        # actually affect the notebook module's ns
        save_user_ns = self.shell.user_ns
        self.shell.user_ns = mod.__dict__

        try:
            for cell in nb.worksheets[0].cells:
                if cell.cell_type == 'code' and cell.language == 'python':
                    # transform the input to executable Python
                    code = self.shell.input_transformer_manager.transform_cell(cell.input)
                    # run the code in themodule
                    exec code in mod.__dict__
        finally:
            self.shell.user_ns = save_user_ns
        return mod

class NotebookFinder(object):
    """Module finder that locates IPython Notebooks"""
    def __init__(self):
        self.loaders = {}

    def find_module(self, fullname, path=None):
        nb_path = find_notebook(fullname, path)
        if not nb_path:
            return

        key = path
        if path:
            # lists aren't hashable
            key = os.path.sep.join(path)

        if key not in self.loaders:
            self.loaders[key] = NotebookLoader(path)
        return self.loaders[key]

# --------------

from pygments import highlight
from pygments.lexers import PythonLexer
from pygments.formatters import HtmlFormatter

from IPython.display import display, HTML

formatter = HtmlFormatter()
lexer = PythonLexer()

# publish the CSS for pygments highlighting
display(HTML("""
<style type='text/css'>
%s
</style>
""" % formatter.get_style_defs()
))

def show_notebook(fname):
    """display a short summary of the cells of a notebook"""
    with io.open(fname, 'r', encoding='utf-8') as f:
        nb = current.read(f, 'json')
    html = []
    for cell in nb.worksheets[0].cells:
        html.append("<h4>%s cell</h4>" % cell.cell_type)
        if cell.cell_type == 'code':
            html.append(highlight(cell.input, lexer, formatter))
        else:
            html.append("<pre>%s</pre>" % cell.source)
    display(HTML('\n'.join(html)))

# Example
#show_notebook(os.path.join("nbimp", "mynotebook.ipynb"))

sys.meta_path.append(NotebookFinder())