2 files changed, 18 insertions, 6 deletions

diff --git a/glucometer.py b/glucometer.py
index 6ca2cf3..5e05a77 100755
--- a/glucometer.py
+++ b/glucometer.py
@@ -38,6 +38,10 @@ def main():
   parser_dump.add_argument(
     '--unit', action='store', choices=common.VALID_UNITS,
     help='Select the unit to use for the dumped data.')
+  parser_dump.add_argument(
+    '--sort-by', action='store', default='timestamp',
+    choices=common.Reading._fields,
+    help='Field to order the dumped data by.')
 
   parser_date = subparsers.add_parser(
     'datetime', help='Reads or sets the date and time of the glucometer.')
@@ -58,7 +62,13 @@ def main():
       if unit is None:
         unit = device.get_glucose_unit()
 
-      for reading in device.get_readings():
+      readings = device.get_readings()
+
+      if args.sort_by is not None:
+        readings = sorted(
+          readings, key=lambda reading: getattr(reading, args.sort_by))
+
+      for reading in readings:
         print('"%s","%.2f","%s","%s"' % (
           reading.timestamp, reading.get_value_as(unit),
           reading.meal, reading.comment))
diff --git a/glucometerutils/common.py b/glucometerutils/common.py
index 797fc6e..825dea1 100644
--- a/glucometerutils/common.py
+++ b/glucometerutils/common.py
@@ -6,6 +6,8 @@ __email__ = 'flameeyes@flameeyes.eu'
 __copyright__ = 'Copyright © 2013, Diego Elio Pettenò'
 __license__ = 'MIT'
 
+import collections
+
 # Constants for units
 UNIT_MGDL = 'mg/dL'
 UNIT_MMOLL = 'mmol/L'
@@ -48,8 +50,10 @@ def convert_glucose_unit(value, from_unit, to_unit=None):
   else:
     return round(value * 18.0, 0)
 
+_ReadingBase = collections.namedtuple(
+  '_ReadingBase', ['timestamp', 'value', 'meal', 'comment'])
 
-class Reading(object):
+class Reading(_ReadingBase):
   def __init__(self, timestamp, value, meal='', comment=''):
     """Constructor for the reading object.
 
@@ -63,10 +67,8 @@ class Reading(object):
     because at least most of the LifeScan devices report the raw data in this
     format.
     """
-    self.timestamp = timestamp
-    self.value = value
-    self.meal = meal
-    self.comment = comment
+    super(Reading, self).__init__(
+      timestamp=timestamp, value=value, meal=meal, comment=comment)
 
   def get_value_as(self, to_unit):
     """Returns the reading value as the given unit.