initial commit

1 files changed, 107 insertions, 0 deletions

diff --git a/jsonpointer.py b/jsonpointer.py
new file mode 100644
index 0000000..b1f0d72
--- /dev/null
+++ b/jsonpointer.py
@@ -0,0 +1,107 @@
+# -*- coding: utf-8 -*-
+#
+# python-json-pointer - An implementation of the JSON Pointer syntax
+# https://github.com/stefankoegl/python-json-pointer
+#
+# Copyright (c) 2011 Stefan Kögl <stefan@skoegl.net>
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+# 3. The name of the author may not be used to endorse or promote products
+#    derived from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#
+
+""" Identify specific nodes in a JSON document according to
+http://tools.ietf.org/html/draft-pbryan-zyp-json-pointer-00 """
+
+# Will be parsed by setup.py to determine package metadata
+__author__ = 'Stefan Kögl <stefan@skoegl.net>'
+__version__ = '0.1'
+__website__ = 'https://github.com/stefankoegl/python-json-pointer'
+__license__ = 'Modified BSD License'
+
+
+import urllib
+
+
+class JsonPointerException(Exception):
+    pass
+
+
+def resolve_pointer(doc, pointer):
+    """
+    Resolves pointer against doc and returns the referenced object
+
+    >>> obj = {"foo": {"anArray": [ {"prop": 44}], "another prop": {"baz": "A string" }}}
+
+    >>> resolve_pointer(obj, '/') == obj
+    True
+
+    >>> resolve_pointer(obj, '/foo')
+    {'another prop': {'baz': 'A string'}, 'anArray': [{'prop': 44}]}
+
+    >>> resolve_pointer(obj, '/foo/another%20prop')
+    {'baz': 'A string'}
+
+    >>> resolve_pointer(obj, '/foo/another%20prop/baz')
+    'A string'
+
+    >>> resolve_pointer(obj, '/foo/anArray/0')
+    {'prop': 44}
+    """
+
+    parts = pointer.split('/')
+    if parts.pop(0) != '':
+        raise JsonPointerException('location must starts with /')
+
+    parts = map(urllib.unquote, parts)
+
+    for part in parts:
+        doc = walk(doc, part)
+
+    return doc
+
+
+def walk(doc, part):
+    """ Walks one step in doc and returns the referenced part """
+
+    if not part:
+        return doc
+
+    # Its not clear if a location "1" should be considered as 1 or "1"
+    # We prefer the integer-variant if possible
+    part_variants = _try_parse(part) + [part]
+
+    for variant in part_variants:
+        try:
+            return doc[variant]
+        except:
+            continue
+
+    raise JsonPointerException("'%s' not found in %s" % (part, doc))
+
+
+def _try_parse(val, cls=int):
+    try:
+        return [cls(val)]
+    except:
+        return []