'''
====================================================================
Copyright (c) 2003-2009 Barry A Scott. All rights reserved.
This software is licensed as described in the file LICENSE.txt,
which you should have received as part of this distribution.
====================================================================
'''
_debug_parse_time = 0
class DateTimeSyntaxError( Exception ):
def __init__( self, reason ):
Exception.__init__( self )
self._reason = reason
def reason( self ):
return self._reason
def __str__( self ):
return self._reason
class DateSyntaxError( DateTimeSyntaxError ):
def __init__( self, reason ):
DateTimeSyntaxError.__init__( self, reason )
class TimeSyntaxError( DateTimeSyntaxError ):
def __init__( self, reason ):
DateTimeSyntaxError.__init__( self, reason )
def parse_time( time_string ):
"""parse_time( time_string )
returns the UTC time represented by time_string
british locale defaults used
formats understood for a date are:
dayname - today, yesterday, monday, tuesday...
dd/mm/yy[yy] - numeric date
dd-mmm-yy[yy] - month as jan,feb,etc...
n units - n units of time ago
where units are:
seconds
minutes
hours
days
weeks
months
years
formats understood for time are:
HH:MM - absolute time in hours and minutes
HH:MM:SS - absolute time in hours, minutes and seconds
formats understood for data and time are:
adate atime - absolute date followed by absolute time
rdate atime - relative date followed by absolute time
atime adate - absolute time followed by absolute date
atime rdate - absolute time followed by relative date
"""
if _debug_parse_time: print( '* parse_time: time_string=',time_string )
date = DateConversions()
have_date = 0
have_time = 0
table = string.maketrans("-/"," ")
time_list = string.split( string.translate( time_string, table ) )
try:
day_time = convert_time( time_list[0] )
time_list = time_list[1:]
if _debug_parse_time:
print( '* parse_time: Time_list[0] is a time' )
except TimeSyntaxError:
try:
day_time = convert_time( time_list[-1] )
time_list = time_list[:-1]
if _debug_parse_time:
print( '* parse_time: Time_list[-1] is a time' )
except TimeSyntaxError:
day_time = 0
if len(time_list) == 0:
# default to today at time
result = date.midnight + day_time
if _debug_parse_time: print( '* parse_time: 1 return',format_time(result) )
return result
match_type = date.numeric_type
matches = []
for word in time_list:
day_matches = date.findMatchingDateName( word )
if len(day_matches) == 0:
raise DateSyntaxError( "%s unknown date word" % word )
if date.isAmbiguous( day_matches ):
raise DateSyntaxError( date.reportAmbiguity( word, day_matches ) )
this_type = date.typeOfMatch( day_matches )
if this_type != date.numeric_type:
if match_type == date.numeric_type:
match_type = this_type
elif match_type != this_type:
raise DateSyntaxError( "ambiguous mix of unit and month names" )
matches.append( day_matches[0] )
if _debug_parse_time: print( '* parse_time: matches=',matches )
if match_type == date.day_type:
if len(matches) != 1:
raise DateSyntaxError( "too many day words" )
day_matches = matches[0]
result = date.convertDay( day_matches[2] ) + day_time
if _debug_parse_time: print( '* parse_time: 2 return',format_time(result) )
return result
if match_type == date.unit_type:
# expect a set of pair of <num> <unit>
if _debug_parse_time >= 2:
print( 'matches',matches )
if (len(matches)&1) == 1:
raise DateSyntaxError( 'must have an even number parameters when using time units' )
time_offset = 0
for index in range( 0, len(matches), 2 ):
value_tuple = matches[index]
unit_tuple = matches[index+1]
if value_tuple[1] != date.numeric_type:
raise DateSyntaxError( 'Expecting a number of units' )
if unit_tuple[1] != date.unit_type:
raise DateSyntaxError( 'Expecting a unit name' )
value = value_tuple[2]
unit = unit_tuple[2]
time_offset = time_offset + value*unit
result = date.now - time_offset
if _debug_parse_time: print( '* parse_time: 3 return',format_time(result) )
return result
if match_type == date.month_type:
# absolute date
if len(matches) < 1 or len(matches) > 3:
raise DateSyntaxError( 'too many date parts' )
day = -1
month = -1
year = -1
num_month_types = 0
for entry in matches:
if date.isMonth( entry ):
num_month_types = num_month_types + 1
if num_month_types != 1:
raise DateSyntaxError( 'too many months in the date string' )
if date.isMonth( matches[0] ):
month = matches[0][2]
day = matches[1][2]
if len(matches) == 3:
year = matches[2][2]
else:
day = matches[0][2]
if matches[1][1] != date.month_type:
raise DateSyntaxError( 'expecting month as first or second part of date' )
month = matches[1][2]
if len(matches) == 3:
year = matches[2][2]
seconds = day_time%60
minutes = (day_time/60)%60
hours = day_time/60/60
result = date.absDate( day, month, year, hours, minutes, seconds )
if _debug_parse_time: print( '* parse_time: 4 return',format_time(result) )
return result
if match_type == date.numeric_type and len(matches) == 3:
# assume its in locale order - which is assumed to be D M Y
day = matches[0][2]
month = matches[1][2]
year = matches[2][2]
seconds = day_time%60
minutes = (day_time/60)%60
hours = day_time/60/60
result = date.absDate( day, month, year, hours, minutes, seconds )
if _debug_parse_time: print( '* parse_time: 4 return',format_time(result) )
return result
raise DateSyntaxError( 'cannot understand date and time string ' + time_string )
def convert_time( time_str ):
time_list = string.split( time_str, ':' )
if len(time_list) < 2:
# not a time - no ":"
raise TimeSyntaxError( "Not a time" )
if len(time_list) > 3:
raise TimeSyntaxError( "Too many time parts" )
hour = time_list[0]
minute = time_list[1]
second = '0'
if len(time_list) > 2:
second = time_list[2]
try:
hour = string.atoi( hour )
minute = string.atoi( minute )
second = string.atoi( second )
except:
return -1
if( hour < 0 or hour > 23 ):
raise TimeSyntaxError( "hour value of %d invalid" % hour )
if( minute < 0 or minute > 59 ):
raise TimeSyntaxError( "minutes value of %d invalid" % hour )
if( second < 0 or second > 59 ):
raise TimeSyntaxError( "seconds value of %d invalid" % hour )
day_time = (hour*60 + minute)*60 + second
return day_time
class DateConversions:
seconds_in_one_day = 24*60*60
day_type = 1
month_type = 2
unit_type = 3
numeric_type = 4
date_names = [
# day names
('today', day_type, 0),
('yesterday', day_type, -1),
('monday', day_type, 1),
('tuesday', day_type, 2),
('wednesday', day_type, 3),
('thursday', day_type, 4),
('friday', day_type, 5),
('saturday', day_type, 6),
('sunday', day_type, 7),
# month names
('january', month_type, 1),
('feburary', month_type, 2),
('march', month_type, 3),
('april', month_type, 4),
('may', month_type, 5),
('june', month_type, 6),
('july', month_type, 7),
('august', month_type, 8),
('september', month_type, 9),
('october', month_type, 10),
('november', month_type, 11),
('december', month_type, 12),
# unit names
('seconds', unit_type, 1),
('minutes', unit_type, 60),
('hours', unit_type, 60*60),
('days', unit_type, 24*60*60.),
('weeks', unit_type, 7*24*60*60),
('months', unit_type, 30*24*60*60),
('years', unit_type, 365*24*60*60)
]
def __init__( self ):
self.now = time.time()
self.year, self.month, self.day, self.hour, self.minute, self.second, self.weekday, self.julian, self.dst = time.localtime( self.now )
self.midnight = time.mktime(
(self.year, self.month, self.day,
0, 0, 0,
self.weekday, self.julian, self.dst) )
def convertDay( self, day_offset ):
if day_offset == 0: # today
return self.midnight
elif day_offset == -1: # yesterday
return self.midnight - self.seconds_in_one_day
else:
# day of week
offset = day_offset - self.weekday - 1
# make sure its in the past
if offset >= 0:
offset = offset - 7
return self.midnight + offset*self.seconds_in_one_day
def absDate( self, day, month, year, hour=0, minute=0, second=0 ):
future_check = 0
if year < 0:
year = self.year
future_check = 1
elif year < 70:
year = year + 2000
elif year < 100:
year = year + 1900
try:
date = time.mktime(
(year, month, day,
hour, minute, second,
self.weekday, self.julian, -1) )
except OverflowError:
raise DateSyntaxError( 'cannot convert date and time year=%d/month=%d/day=%d %d:%d:%d' %
(year, month, day, hour, minute, second) )
if date > self.now and future_check:
year = year - 1
try:
date = time.mktime(
(year, month, day,
hour, minute, second,
self.weekday, self.julian, -1) )
except OverflowError:
raise DateSyntaxError( 'cannot convert date and time %d/%d/%d %d:%d:%d' %
(year, month, day, hour, minute, second) )
return date
def findMatchingDateName( self, name ):
try:
value = string.atoi( name )
return [(name, self.numeric_type, value )]
except:
pass
matches = []
name_len = len(name)
for entry in self.date_names:
entry_name = entry[0]
if len(entry_name) >= name_len and entry_name[0:name_len] == name:
matches.append( entry )
return matches
def typeOfMatch( self, matches ):
return matches[0][1]
def isAmbiguous( self, matches ):
return len(matches) > 1
def isDay( self, matches ):
return matches[1] == self.day_type
def isMonth( self, matches ):
return matches[1] == self.month_type
def isUnit( self, matches ):
return matches[1] == self.unit_type
def isNumeric( self, matches ):
return matches[1] == self.numeric_type
def reportAmbiguity( self, name, tuples ):
names = map( lambda t: t[0], tuples )
return "%s is ambiguous, it matches: %s" % (name, string.join( names, ', ' ))
