Add datetime helpers

LdapServer.py

@@ -1,8 +1,12 @@
 #!/usr/bin/python
 
+import copy
+import datetime
+import dateutil
 import ldap
 import ldap.modlist as modlist
 import logging
+import pytz
 
 class LdapServer(object):
 
@@ -144,3 +148,57 @@ class LdapServer(object):
 class LdapServerException(BaseException):
 	def __init__(self,msg):
 		BaseException.__init__(self, msg)
+
+#
+# Helpers
+#
+def parse_datetime(value, to_timezone=None, default_timezone=None):
+	assert to_timezone is None or isinstance(to_timezone, datetime.tzinfo), 'to_timezone must be None or datetime.tzinfo object (not %s)' % type(value)
+	assert default_timezone is None or isinstance(default_timezone, datetime.tzinfo) or isinstance(default_timezone, pytz.tzinfo.DstTzInfo) or isinstance(default_timezone, str), 'default_timezone parameter must be None, a string, a pytz.tzinfo.DstTzInfo or a datetime.tzinfo object (not %s)' % type(from_timezone)
+	date = dateutil.parser.parse(value, dayfirst=False)
+	if not date.tzinfo:
+		if not default_timezone:
+			default_timezone = pytz.utc
+		elif isinstance(default_timezone, str):
+			default_timezone = pytz.timezone(default_timezone)
+		if isinstance(default_timezone, pytz.tzinfo.DstTzInfo):
+			date = default_timezone.localize(date)
+		elif isinstance(from_timezone, datetime.tzinfo):
+			date = date.replace(tzinfo=default_timezone)
+		else:
+			raise Exception("It's not supposed to happen!")
+	if to_timezone:
+		return date.astimezone(totimezone)
+	return date
+
+def parse_date(value, to_timezone=None):
+	return parse_datetime(value, to_timezone).date()
+
+def format_datetime(value, from_timezone=None, to_timezone=None):
+	assert isinstance(value, datetime.datetime), 'First parameter must be an datetime.datetime object (not %s)' % type(value)
+	assert from_timezone is None or isinstance(from_timezone, datetime.tzinfo) or isinstance(from_timezone, pytz.tzinfo.DstTzInfo) or isinstance(from_timezone, str), 'from_timezone parameter must be None, a string, a pytz.tzinfo.DstTzInfo or a datetime.tzinfo object (not %s)' % type(from_timezone)
+	assert to_timezone is None or isinstance(to_timezone, datetime.tzinfo), 'to_timezone must be None or datetime.tzinfo object (not %s)' % type(value)
+	if not value.tzinfo:
+		if not from_timezone:
+			from_timezone = dateutil.tz.tzlocal()
+		elif isinstance(from_timezone, str):
+			from_timezone = pytz.timezone(from_timezone)
+		if isinstance(from_timezone, pytz.tzinfo.DstTzInfo):
+			from_value = from_timezone.localize(value)
+		elif isinstance(from_timezone, datetime.tzinfo):
+			from_value = value.replace(tzinfo=from_timezone)
+		else:
+			raise Exception("It's not supposed to happen!")
+	else:
+		from_value = copy.deepcopy(value)
+	if not to_timezone:
+		to_timezone = pytz.utc
+	to_value = from_value.astimezone(to_timezone)
+	datestring = to_value.strftime(value, '%Y%m%d%H%M%S%z')
+	if datestring.endswith('+0000'):
+		datestring = datestring.replace('+0000', 'Z')
+	return datestring
+
+def format_date(value, from_timezone=None, to_timezone=None):
+	assert isinstance(value, datetime.date), 'First parameter must be an datetime.date object (not %s)' % type(value)
+	return format_datetime(datetime.datetime.combine(value, datetime.datetime.min.time()), from_timezone, to_timezone)