Merge pull request #3525 from minrk/utc

Fix basic timezone info

minor tweaks to jsonutil, to include timezone info if available
add IPython.utils.tz, which just has basic info for making utcnow(), etc. include tzinfo in the datetime object
use this tzinfo in the last_modified keys in notebook managers, which fixes Firefox's timezone offset for checkpoints

IPython/utils/tz.py

@@ -0,0 +1,46 b''
+# encoding: utf-8
+"""
+Timezone utilities
+
+Just UTC-awareness right now
+"""
+
+#-----------------------------------------------------------------------------
+#  Copyright (C) 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
+#-----------------------------------------------------------------------------
+
+from datetime import tzinfo, timedelta, datetime
+
+#-----------------------------------------------------------------------------
+# Code
+#-----------------------------------------------------------------------------
+# constant for zero offset
+ZERO = timedelta(0)
+
+class tzUTC(tzinfo):
+    """tzinfo object for UTC (zero offset)"""
+
+    def utcoffset(self, d):
+        return ZERO
+
+    def dst(self, d):
+        return ZERO
+
+UTC = tzUTC()
+
+def utc_aware(unaware):
+    """decorator for adding UTC tzinfo to datetime's utcfoo methods"""
+    def utc_method(*args, **kwargs):
+        dt = unaware(*args, **kwargs)
+        return dt.replace(tzinfo=UTC)
+    return utc_method
+
+utcfromtimestamp = utc_aware(datetime.utcfromtimestamp)
+utcnow = utc_aware(datetime.utcnow)

IPython/html/services/notebooks/azurenbmanager.py

@@ -26,7 +26,7 b' from tornado import web'
 from .nbmanager import NotebookManager
 from IPython.nbformat import current
 from IPython.utils.traitlets import Unicode, Instance
-
+from IPython.utils import tz
 
 #-----------------------------------------------------------------------------
 # Classes
@@ -98,7 +98,7 b' class AzureNotebookManager(NotebookManager):'
             raise web.HTTPError(500, u'Unreadable JSON notebook.')
         # Todo: The last modified should actually be saved in the notebook document.
         # We are just using the current datetime until that is implemented.
-        last_modified = datetime.datetime.utcnow()
+        last_modified = tz.utcnow()
         return last_modified, nb
 
     def write_notebook_object(self, nb, notebook_id=None):

IPython/html/services/notebooks/filenbmanager.py

@@ -28,6 +28,7 b' from tornado import web'
 from .nbmanager import NotebookManager
 from IPython.nbformat import current
 from IPython.utils.traitlets import Unicode, Dict, Bool, TraitError
+from IPython.utils import tz
 
 #-----------------------------------------------------------------------------
 # Classes
@@ -139,7 +140,7 b' class FileNotebookManager(NotebookManager):'
     def read_notebook_object_from_path(self, path):
         """read a notebook object from a path"""
         info = os.stat(path)
-        last_modified = datetime.datetime.utcfromtimestamp(info.st_mtime)
+        last_modified = tz.utcfromtimestamp(info.st_mtime)
         with open(path,'r') as f:
             s = f.read()
             try:
@@ -281,7 +282,7 b' class FileNotebookManager(NotebookManager):'
         """construct the info dict for a given checkpoint"""
         path = self.get_checkpoint_path(notebook_id, checkpoint_id)
         stats = os.stat(path)
-        last_modified = datetime.datetime.utcfromtimestamp(stats.st_mtime)
+        last_modified = tz.utcfromtimestamp(stats.st_mtime)
         info = dict(
             checkpoint_id = checkpoint_id,
             last_modified = last_modified,

IPython/utils/jsonutil.py

@@ -33,7 +33,7 b" next_attr_name = '__next__' if py3compat.PY3 else 'next'"
 
 # timestamp formats
 ISO8601="%Y-%m-%dT%H:%M:%S.%f"
-ISO8601_PAT=re.compile(r"^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d+$")
+ISO8601_PAT=re.compile(r"^(\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}\.\d+)Z?([\+\-]\d{2}:?\d{2})?$")
 
 #-----------------------------------------------------------------------------
 # Classes and functions
@@ -71,8 +71,12 b' def extract_dates(obj):'
     elif isinstance(obj, (list, tuple)):
         obj = [ extract_dates(o) for o in obj ]
     elif isinstance(obj, basestring):
-        if ISO8601_PAT.match(obj):
-            obj = datetime.strptime(obj, ISO8601)
+        m = ISO8601_PAT.match(obj)
+        if m:
+            # FIXME: add actual timezone support
+            # this just drops the timezone info
+            notz = m.groups()[0]
+            obj = datetime.strptime(notz, ISO8601)
     return obj
 
 def squash_dates(obj):
@@ -84,13 +88,13 b' def squash_dates(obj):'
     elif isinstance(obj, (list, tuple)):
         obj = [ squash_dates(o) for o in obj ]
     elif isinstance(obj, datetime):
-        obj = obj.strftime(ISO8601)
+        obj = obj.isoformat()
     return obj
 
 def date_default(obj):
     """default function for packing datetime objects in JSON."""
     if isinstance(obj, datetime):
-        return obj.strftime(ISO8601)
+        return obj.isoformat()
     else:
         raise TypeError("%r is not JSON serializable"%obj)
 

IPython/utils/tests/test_jsonutil.py

@@ -11,6 +11,7 b''
 # Imports
 #-----------------------------------------------------------------------------
 # stdlib
+import datetime
 import json
 from base64 import decodestring
 
@@ -19,6 +20,7 b' import nose.tools as nt'
 
 # our own
 from IPython.testing import decorators as dec
+from IPython.utils import jsonutil, tz
 from ..jsonutil import json_clean, encode_images
 from ..py3compat import unicode_to_str, str_to_bytes
 
@@ -94,6 +96,33 b' def test_lambda():'
     assert '<lambda>' in jc
     json.dumps(jc)
 
+def test_extract_dates():
+    timestamps = [
+        '2013-07-03T16:34:52.249482',
+        '2013-07-03T16:34:52.249482Z',
+        '2013-07-03T16:34:52.249482Z-0800',
+        '2013-07-03T16:34:52.249482Z+0800',
+        '2013-07-03T16:34:52.249482Z+08:00',
+        '2013-07-03T16:34:52.249482Z-08:00',
+        '2013-07-03T16:34:52.249482-0800',
+        '2013-07-03T16:34:52.249482+0800',
+        '2013-07-03T16:34:52.249482+08:00',
+        '2013-07-03T16:34:52.249482-08:00',
+    ]
+    extracted = jsonutil.extract_dates(timestamps)
+    ref = extracted[0]
+    for dt in extracted:
+        nt.assert_true(isinstance(dt, datetime.datetime))
+        nt.assert_equal(dt, ref)
+
+def test_date_default():
+    data = dict(today=datetime.datetime.now(), utcnow=tz.utcnow())
+    jsondata = json.dumps(data, default=jsonutil.date_default)
+    nt.assert_in("+00", jsondata)
+    nt.assert_equal(jsondata.count("+00"), 1)
+    extracted = jsonutil.extract_dates(json.loads(jsondata))
+    for dt in extracted.values():
+        nt.assert_true(isinstance(dt, datetime.datetime))
 
 def test_exception():
     bad_dicts = [{1:'number', '1':'string'},