* Added first implementation (and test harness) for idatetime

datatype.

datetime0_idt.py

@@ -0,0 +1,103 @@
+#
+# wpylib.datetime0_idt
+# Created: 20141015
+# Wirawan Purwanto
+#
+# Simple date/time stamp using 64-bit integer.
+# This module is an internal module; the exported name will
+# be put in wpylib.datetime module.
+#
+
+"""
+wplib.datetime0_idt module
+
+Simple date/time stamp using 64-bit integer.
+The primary motivation of creating this class is to store date/time
+information in the most compact way, while keeping the ease of
+human readability.
+
+The internal format is very simple:
+
+YYYYMMDDhhmmssfff
+
+where:
+ - YYYY = year (0 < YYYY <= 9999)
+ - MM   = month (1 <= MM <= 12)
+ - DD   = day
+ - hh   = hour (0 <= hh < 24)
+ - mm   = minutes
+ - ss   = seconds
+ - fff  = milliseconds
+
+The time is always expressed in terms of UTC to eliminate ambiguity of
+time zone, daylight savings time, etc.
+CAVEAT: The resolution of the time is only on the order of millisecond.
+
+This is a 17-decimal-digit integer, which fits in a 64-bit range (9.22e+18).
+
+"""
+
+from wpylib.params import struct
+
+
+class idatetime(object):
+  """Simple 8-byte integer representation of a date/time stamp.
+  """
+  def __init__(self, idt=None):
+    if idt != None:
+      self.idt = idt
+
+  def validate(self):
+    raise NotImplementedError
+
+  def split_values(self):
+    """Splits the compact datetime into components.
+    Warning: the values are NOT validated.
+    """
+    idt = self.idt
+    s = str(idt)
+    R = struct()
+    #R.YYYY, R.MM, R.DD, R.hh, R.mm, R.ss, R.fff # names are too cryptic
+    # Use same member names as in datetime (in sofar it is possible):
+    R.year, R.month, R.day, R.hour, R.minute, R.second, R.millisecond = map(int, [
+      s[:-13],    # year
+      s[-13:-11], # month
+      s[-11:-9],  # day
+      s[-9:-7],   # hour
+      s[-7:-5],   # min
+      s[-5:-3],   # sec
+      s[-3:]      # millisec
+    ])
+    R.microsecond = R.millisecond * 1000
+    return R
+
+  def to_datetime(self):
+    """Converts the object value to standard python datetime object.
+    """
+    from datetime import datetime
+    R = self.split_values()
+    dt = datetime(R.year, R.month, R.day, R.hour, R.minute, R.second, R.microsecond)
+    '''
+    idt = self.idt
+    s = str(idt)
+    YYYY, MM, DD, hh, mm, ss, ms = map(int, [
+      s[:-13],    # year
+      s[-13:-11], # month
+      s[-11:-9],  # day
+      s[-9:-7],   # hour
+      s[-7:-5],   # min
+      s[-5:-3],   # sec
+      s[-3:]      # millisec
+    ])
+    dt = datetime(YYYY, MM, DD, hh, mm, ss, fff*1000)
+    '''
+    return dt
+
+  def str_iso8601(self):
+    """Outputs the object according to ISO-8601 combined date/time format.
+    No time zone is shown."""
+    R = self.split_values()
+    fmt = "%(year)04d-%(month)02d-%(day)02dT%(hour)02d:%(minute)02d:%(second)02d.%(millisecond)03d"
+    return fmt % R
+
+