wxPython/samples/ide/activegrid/util/datetimeparser.py

   1 #----------------------------------------------------------------------------
   2 # Name:         datetimeparser.py
   3 #
   4 # Purpose:      - Instantiate datetime.datetime/date instance from a string
   5 #                 date representation.
   6 #                 Uses dateutil from http://labix.org/python-dateutil.
   7 #
   8 #               - Creates string representation of datetime/date instance.
   9 #
  10 #
  11 # Author:       Simon Toens
  12 #
  13 # Created:      28-Feb-06
  14 # CVS-ID:
  15 # Copyright:    (c) 2005 ActiveGrid, Inc.
  16 # License:      wxWindows License
  17 #----------------------------------------------------------------------------
  18
  19 import datetime
  20
  21 try:
  22     import dateutil.parser
  23     DATEUTIL_INSTALLED = True
  24 except ImportError:
  25     DATEUTIL_INSTALLED = False
  26
  27 ISO_8601_DATE_FORMAT = "%Y-%m-%d"
  28 ISO_8601_TIME_FORMAT = "%H:%M:%S"
  29 ISO_8601_DATETIME_FORMAT = "%s %s" %(ISO_8601_DATE_FORMAT,
  30                                      ISO_8601_TIME_FORMAT)
  31
  32 DEFAULT_DATETIME = datetime.datetime(1, 1, 1, 0, 0, 0, 0)
  33
  34
  35 def format(dateobj, formatstr=None):
  36     if (formatstr != None and _isDateTimeObject(dateobj)):
  37         return dateobj.strftime(str(formatstr))
  38     return str(dateobj)
  39
  40
  41 def parse(datestr, formatstr=None, asdate=False, astime=False):
  42     """Instantiates and returns a datetime instance from the datestr datetime
  43        representation.
  44
  45        Optionally, a format string may be used. The format is only loosely
  46        interpreted, its only purpose beeing to determine if the year is first
  47        or last in datestr, and whether the day is in front or follows the
  48        month. If no formatstr is passed in, dateutil tries its best to parse
  49        the datestr. The default date format is YYYY-mm-dd HH:SS.
  50
  51        If asdate is True, returns a date instance instead of a datetime
  52        instance, if astime is True, returns a time instance instead of a
  53        datetime instance."""
  54
  55
  56     dayfirst, yearfirst = _getDayFirstAndYearFirst(formatstr)
  57
  58     rtn = None
  59
  60     try:
  61         if DATEUTIL_INSTALLED:
  62             rtn = dateutil.parser.parse(str(datestr), fuzzy=True,
  63                                         dayfirst=dayfirst, yearfirst=yearfirst,
  64                                         default=DEFAULT_DATETIME)
  65         else:
  66             rtn = DEFAULT_DATETIME
  67     except:
  68         rtn = DEFAULT_DATETIME
  69
  70     if (asdate and isinstance(rtn, datetime.datetime)):
  71         rtn = datetime.date(rtn.year, rtn.month, rtn.day)
  72     elif (astime and isinstance(rtn, datetime.datetime)):
  73         rtn = datetime.time(rtn.hour, rtn.minute, rtn.second, rtn.microsecond)
  74
  75     return rtn
  76
  77
  78 def _isDateTimeObject(obj):
  79     return (isinstance(obj, datetime.datetime) or
  80             isinstance(obj, datetime.date) or
  81             isinstance(obj, datetime.time))
  82
  83
  84 def _getDayFirstAndYearFirst(formatstr):
  85     dayFirst = False
  86     yearFirst = False
  87
  88     gotYear = False
  89     gotMonth = False
  90     gotDay = False
  91
  92     if (formatstr == None):
  93         formatstr = ""
  94
  95     for c in formatstr:
  96         if (c.lower() == "y"):
  97             if (gotYear):
  98                 continue
  99             if (not gotDay and not gotMonth):
 100                 yearFirst = True
 101             gotYear = True
 102
 103         elif (c.lower() == "m"):
 104             if (gotMonth):
 105                 continue
 106             if (not gotDay):
 107                 dayFirst = False
 108             gotMonth = True
 109
 110         elif (c.lower() == "d"):
 111             if (gotDay):
 112                 continue
 113             if (not gotMonth):
 114                 dayFirst = True
 115             gotDay = True
 116
 117
 118     return dayFirst, yearFirst