Add support for a 'unixepoch' form of Date (patch included)

[GoogleCodeExporter]

Please consider adding support for a Unix Epoch form of Date (unixepoch), as 
used by sqlite3. This is very handy for sysadmin-type stuff, and I'm already 
using a modified version of the Python library supporting it.

Here is a context diff showing how to implement it:

*** google-visualization-python/gviz_api.py      Thu Oct  8 06:00:05 2009
--- with-unixepoch-support/gviz_api.py     Mon Oct 18 17:08:11 2010
***************
*** 185,192 ****

      Args:
        value: The value which should be converted
!       value_type: One of "string", "number", "boolean", "date", "datetime" or
!                   "timeofday".
        escape_func: The function to use for escaping strings.

      Returns:
--- 185,192 ----

      Args:
        value: The value which should be converted
!       value_type: One of "string", "number", "boolean", "date", "datetime",
!                   "timeofday" or "unixepoch".
        escape_func: The function to use for escaping strings.

      Returns:
***************
*** 264,269 ****
--- 264,274 ----
          raise DataTableException("Wrong type %s when expected time" % t_value)
        return "[%d,%d,%d]" % (value.hour, value.minute, value.second)

+     elif value_type == "unixepoch":
+       if not isinstance(value, (int, long)):
+         raise DataTableException("Wrong type %s when expected seconds since 
unix epoch" % t_value)
+       return "new Date(%d)" % (value*1000)
+
      elif value_type == "datetime":
        if not isinstance(value, datetime.datetime):
          raise DataTableException("Wrong type %s when expected datetime" %
***************
*** 335,341 ****
            if len(description) > 4:
              raise DataTableException("Description error: tuple of length > 4")
      if desc_dict["type"] not in ["string", "number", "boolean",
!                                  "date", "datetime", "timeofday"]:
        raise DataTableException(
            "Description error: unsupported type '%s'" % desc_dict["type"])
      return desc_dict
--- 340,346 ----
            if len(description) > 4:
              raise DataTableException("Description error: tuple of length > 4")
      if desc_dict["type"] not in ["string", "number", "boolean",
!                                  "date", "datetime", "timeofday", 
"unixepoch"]:
        raise DataTableException(
            "Description error: unsupported type '%s'" % desc_dict["type"])
      return desc_dict

Original issue reported on code.google.com by Warren.H...@gmail.com on 20 Oct 2010 at 2:52