Adding conversion tool.

Author: rossant

tools/convert_nbformat.py

@@ -0,0 +1,72 @@
+
+import re
+import json
+import os
+import sys
+import os.path as op
+
+from IPython.nbformat import read, convert, write, validate
+
+def get_chapter_number(dir):
+    return int(op.basename(dir)[7:9])
+
+def get_chapter_name(number):
+    return CHAPTER_NAMES[number-1]
+
+def iter_chapters(root):
+    for chapter in sorted([_ for _ in os.listdir(root)
+                            if _.startswith('chapter')]):
+        yield chapter
+
+def iter_recipes(root, dir):
+    files = sorted([_ for _ in os.listdir(op.join(root, dir))
+        if re.match(r'\d{2}\_[^.]+\.ipynb', _)])
+    for file in files:
+        yield file
+
+curdir = op.realpath(op.dirname(os.path.abspath(__file__)))
+root = op.realpath(op.join(curdir, '../notebooks'))
+
+def convert_to_v4(path):
+    nb = read(path, 3)
+    nb_new = convert(nb, 4)
+
+    for cell in nb_new['cells']:
+        if cell.get('metadata', {}) == []:
+            cell['metadata'] = {}
+
+    nb_new["metadata"] ={
+         "kernelspec": {
+          "display_name": "Python 3",
+          "language": "python",
+          "name": "python3"
+         },
+         "language_info": {
+          "codemirror_mode": {
+           "name": "ipython",
+           "version": 3
+          },
+          "file_extension": ".py",
+          "mimetype": "text/x-python",
+          "name": "python",
+          "nbconvert_exporter": "python",
+          "pygments_lexer": "ipython3",
+          "version": "3.4.2"
+         }
+        }
+
+    validate(nb_new)
+    write(nb_new, path)
+
+if __name__ == '__main__':
+
+    for chapter in iter_chapters(root):
+        for recipe in iter_recipes(root, chapter):
+            file = op.join(root, chapter, recipe)
+
+            if recipe in ('01_notebook.ipynb',
+                          '02_pandas.ipynb',
+                          '03_numpy.ipynb',):
+                continue
+            print("converting", file)
+            convert_to_v4(file)