custom_js = """
// nbextensions snippets menu customization.
var json_data;
$.getJSON( "python_snippets.json", function(data) {  
    json_data = data;
});

require(["nbextensions/snippets_menu/main"], function (snippets_menu) {
    console.log('Loading `snippets_menu` customizations from `custom.js`');
    var horizontal_line = '---';
    var snippets_json = json_data
    snippets_menu.options['menus'] = snippets_menu.default_menus;
    snippets_menu.options['menus'][0]['sub-menu'].push(horizontal_line);
    snippets_menu.options['menus'][0]['sub-menu'].push(snippets_json);
    console.log('Loaded `snippets_menu` customizations from `custom.js`');
});
"""

import os
import glob
import re

home = os.path.expanduser("~")
jupyter_home = os.path.join(home,'.jupyter')
jupyter_custom = os.path.join(jupyter_home, 'custom')
test_str = '// nbextensions snippets menu customization.'

if 'custom' in os.listdir(jupyter_home):
    file_names = list(os.walk(jupyter_custom))[0][-1]
    custom_js_file = os.path.join(jupyter_custom,'custom.js')
    if 'custom.js' in file_names:
        # Get the contents of the custom.js file.
        f = open(custom_js_file, 'r')
        contents = f.read()
        f.close()
        # Test to see if the js code has been added.
        if test_str in contents:
            pass
        # If the code hasn't been added then add it.
        else:
            f = open(custom_js_file, 'a+')
            f.write(custom_js)
            f.close()
    # If there is not custom.js file create one and write code to it.
    else:
        f = open(custom_js_file, 'w')
        f.write(custom_js)
        f.close()

import json

ent =dict()
ent['name'] = 'Boiler-plate'
ent['snippet'] = ['import numpy as np','import pandas as pd']

d = dict()
d['name'] = 'Basic'
d['sub-menu'] = [ent]

json_file = json.dumps(d)

# json_file_name = os.path.join(jupyter_custom, 'python_snippets.json')
# f = open(json_file_name, 'w')

f = open('python_snippets.json', 'w')
f.write(json_file)
f.close()

import numpy as np
import pandas as pd