fixed issue 1393, cast_keys in dict for python 2.5 support, thanks Alan and Niphlod

VERSION

@@ -1 +1 @@
-Version 2.4.4-stable+timestamp.2013.03.16.20.52.38
+Version 2.4.4-stable+timestamp.2013.03.17.12.10.29

gluon/dal.py

@@ -7054,15 +7054,13 @@ class DAL(object):
     Example::
 
        db = DAL('sqlite://test.db')
+
+       or
+
+       db = DAL({"uri": ..., "items": ...}) # experimental
+
        db.define_table('tablename', Field('fieldname1'),
                                     Field('fieldname2'))
-
-    (experimental)
-    you can pass a dict object as uri with the uri string
-    and table/field definitions. For an example of valid data check
-    the output of:
-
-    >>> db.as_dict(flat=True, sanitize=False)
     """
 
     def __new__(cls, uri='sqlite://dummy.db', *args, **kwargs):
@@ -7183,6 +7181,28 @@ class DAL(object):
 
         :uri: string that contains information for connecting to a database.
                (default: 'sqlite://dummy.db')
+
+                experimental: you can specify a dictionary as uri
+                parameter i.e. with
+                db = DAL({"uri": "sqlite://storage.sqlite",
+                          "items": {...}, ...})
+
+                for an example of dict input you can check the output
+                of the scaffolding db model with
+
+                db.as_dict()
+
+                Note that for compatibility with Python older than
+                version 2.6.5 you should cast your dict input keys
+                to str due to a syntax limitation on kwarg names.
+                for proper DAL dictionary input you can use one of:
+
+                obj = serializers.cast_keys(dict, [encoding="utf-8"])
+
+                or else (for parsing json input)
+
+                obj = serializers.loads_json(data, unicode_keys=False)
+
         :pool_size: How many open connections to make to the database object.
         :folder: where .table files will be created.
                  automatically set within web2py

gluon/serializers.py

@@ -25,9 +25,52 @@ try:
 except ImportError:
     have_yaml = False
 
-def loads_json(o):
+def cast_keys(o, cast=str, encoding="utf-8"):
+    """ Builds a new object with <cast> type keys
+
+    Arguments:
+        o is the object input
+        cast (defaults to str) is an object type or function
+              which supports conversion such as:
+
+              >>> converted = cast(o)
+
+        encoding (defaults to utf-8) is the encoding for unicode
+                 keys. This is not used for custom cast functions
+
+    Use this funcion if you are in Python < 2.6.5
+    This avoids syntax errors when unpacking dictionary arguments.
+    """
+
+    if isinstance(o, (dict, Storage)):
+        if isinstance(o, dict):
+            newobj = dict()
+        else:
+            newobj = Storage()
+
+        for k, v in o.items():
+            if (cast == str) and isinstance(k, unicode):
+                key = k.encode(encoding)
+            else:
+                key = cast(k)
+            if isinstance(v, (dict, Storage)):
+                value = cast_keys(v, cast=cast, encoding=encoding)
+            else:
+                value = v
+            newobj[key] = value
+    else:
+        raise TypeError("Cannot cast keys: %s is not supported" % \
+                        type(o))
+    return newobj
+
+def loads_json(o, unicode_keys=True, **kwargs):
     # deserialize a json string
-    return json_parser.loads(o)
+    result = json_parser.loads(o, **kwargs)
+    if not unicode_keys:
+        # filter non-str keys in dictionary objects
+        result = cast_keys(result,
+                           encoding=kwargs.get("encoding", "utf-8"))
+    return result
 
 def custom_json(o):
     if hasattr(o, 'custom_json') and callable(o.custom_json):

gluon/tests/test_dal.py

@@ -7,6 +7,7 @@
 import sys
 import os
 import glob
+
 if os.path.isdir('gluon'):
     sys.path.append(os.path.realpath('gluon'))
 else:
@@ -659,7 +660,12 @@ class TestDALDictImportExport(unittest.TestCase):
             import serializers
             dbjson = db.as_json(sanitize=False)
             assert isinstance(dbjson, basestring) and len(dbjson) > 0
-            db3 = DAL(serializers.loads_json(dbjson))
+
+            unicode_keys = True
+            if sys.version < "2.6.5":
+                unicode_keys = False
+            db3 = DAL(serializers.loads_json(dbjson,
+                          unicode_keys=unicode_keys))
             assert hasattr(db3, "person") and hasattr(db3.person, "uuid") and\
             db3.person.uuid.type == db.person.uuid.type
             db3.person.drop()