調用jupyter notebook文件內的函數一種簡單方法

python開發環境jupyter notebook良好的交互式和模塊化受到不少python開發人員的青睞，可是jupyter notebook是以json格式保存文件內容的，而不是python文件那樣的普通格式，因此不能直接被python解析器解析，如何調用.ipynb中的module也成爲一個問題。本文介紹一種方法，使得只要在咱們的工做目錄下放置一個python文件，就能夠正常調用其餘jupyter notebook文件。

Jupyter Notebook官網介紹了一種簡單的方法：http://jupyter-notebook.readthedocs.io/en/latest/examples/Notebook/Importing Notebooks.html

添加jupyter notebook解析文件

    首先，建立一個python文件，例如Ipynb_importer.py，代碼以下：

import io, os,sys,types
from IPython import get_ipython
from nbformat import read
from IPython.core.interactiveshell import InteractiveShell

class NotebookFinder(object):
    """Module finder that locates Jupyter 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]

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 Jupyter 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 Jupyter notebook from %s" % path)

        # load the notebook object
        with io.open(path, 'r', encoding='utf-8') as f:
            nb = read(f, 4)


        # 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
        mod.__dict__['get_ipython'] = get_ipython
        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.cells:
            if cell.cell_type == 'code':
                # transform the input to executable Python
                code = self.shell.input_transformer_manager.transform_cell(cell.source)
                # run the code in themodule
                exec(code, mod.__dict__)
        finally:
            self.shell.user_ns = save_user_ns
        return mod
sys.meta_path.append(NotebookFinder())

調用jupyter notebook module

    在咱們的jupyter notebook文件裏調用Ipynb_importer.py，接下來咱們就能夠像調用普通python文件同樣調用其餘.ipynb文件裏的module了，例若有一個IpynbModule.ipynb文件，裏面定義了一個foo函數：

調用例子以下：

    只要在咱們的工做目錄下放置Ipynb_importer.py文件，就能夠正常調用全部的jupyter notebook文件。 這種方法的本質就是使用一個jupyter notenook解析器先對.ipynb文件進行解析，把文件內的各個模塊加載到內存裏供其餘python文件調用。

參考資料：

http://jupyter-notebook.readthedocs.io/en/latest/examples/Notebook/Importing Notebooks.html