Added top level convert class, updated init.py to load v#s

IPython/nbformat/convert.py

@@ -0,0 +1,68 b''
+"""API for converting notebooks between versions.
+
+Authors:
+
+* Jonathan Frederic
+"""
+
+#-----------------------------------------------------------------------------
+#  Copyright (C) 2008-2013  The IPython Development Team
+#
+#  Distributed under the terms of the BSD License.  The full license is in
+#  the file COPYING, distributed as part of this software.
+#-----------------------------------------------------------------------------
+
+#-----------------------------------------------------------------------------
+# Imports
+#-----------------------------------------------------------------------------
+
+import re
+
+import IPython.nbformat as nbformat
+
+#-----------------------------------------------------------------------------
+# Constants
+#-----------------------------------------------------------------------------
+
+# Get the convert modules for each major revision.
+VERSION_REGEX = re.compile("v[0-9]+")
+version_modules = {}
+for module in dir(nbformat):
+    if VERSION_REGEX.match(module):
+        version_modules[int(module[1:])] = eval('nbformat.' + module + '.convert')
+
+# Get the number of minor versions in each major version and create an ordered
+# list.
+versions = []
+for major in version_modules.keys().sort():
+    current_minor = 0
+    if hasattr(version_modules[major], 'nbformat_minor'):
+        current_minor = version_modules[major].nbformat_minor
+
+    for minor in range(0, current_minor + 1):
+        versions.append((major, minor))
+
+#-----------------------------------------------------------------------------
+# Functions
+#-----------------------------------------------------------------------------
+
+def convert(nb, to_major, to_minor=0):
+    """Convert a notebook node object to a specific version"""
+
+    # Get input notebook version.
+    major = nb.get('nbformat', 1)
+    minor = nb.get('nbformat_minor', 0) # v3+
+
+    # Check if destination is current version, if so return contents
+    if to_major == major and to_minor == minor:
+        return nb
+    elif (to_major, to_minor) in versions:
+        index = versions.indexof((major, minor))
+
+        if to_major > major or (to_major == major and to_minor > minor):
+            to_index = index + 1
+        else:
+            to_index = index - 1
+
+    else:
+        raise Exception("Cannot convert notebook to v%d.%d because that version doesn't exist" % (to_major, to_minor))
  No newline at end of file

IPython/nbformat/__init__.py

@@ -0,0 +1,3 b''
+import v1
+import v2
+import v3