"""
Functions for mathematical datetime operations
(C) 2011-2013 by the GRASS Development Team
This program is free software under the GNU General Public
License (>=v2). Read the file COPYING that comes with GRASS
for details.
:authors: Soeren Gebbert
"""
from datetime import datetime, timedelta
from core import *
import copy
try:
import dateutil.parser as parser
has_dateutil = True
except:
has_dateutil = False
DAY_IN_SECONDS = 86400
SECOND_AS_DAY = 1.1574074074074073e-05
###############################################################################
[docs]def relative_time_to_time_delta(value):
"""Convert the double value representing days
into a timedelta object.
"""
days = int(value)
seconds = value % 1
seconds = round(seconds * DAY_IN_SECONDS)
return timedelta(days, seconds)
###############################################################################
[docs]def time_delta_to_relative_time(delta):
"""Convert the time delta into a
double value, representing days.
"""
return float(delta.days) + float(delta.seconds * SECOND_AS_DAY)
###############################################################################
[docs]def relative_time_to_time_delta_seconds(value):
"""Convert the double value representing seconds
into a timedelta object.
"""
days = (value / 86400)
seconds = int(value % 86400)
return timedelta(days, seconds)
###############################################################################
[docs]def time_delta_to_relative_time_seconds(delta):
"""Convert the time delta into a
double value, representing seconds.
"""
return float(delta.days * DAY_IN_SECONDS) + float(delta.seconds)
###############################################################################
[docs]def decrement_datetime_by_string(mydate, increment, mult=1):
"""Return a new datetime object decremented with the provided
relative dates specified as string.
Additional a multiplier can be specified to multiply the increment
before adding to the provided datetime object.
Usage:
.. code-block:: python
>>> dt = datetime(2001, 1, 1, 0, 0, 0)
>>> string = "31 days"
>>> decrement_datetime_by_string(dt, string)
datetime.datetime(2000, 12, 1, 0, 0)
>>> dt = datetime(2001, 1, 1, 0, 0, 0)
>>> string = "1 month"
>>> decrement_datetime_by_string(dt, string)
datetime.datetime(2000, 12, 1, 0, 0)
>>> dt = datetime(2001, 1, 1, 0, 0, 0)
>>> string = "2 month"
>>> decrement_datetime_by_string(dt, string)
datetime.datetime(2000, 11, 1, 0, 0)
>>> dt = datetime(2001, 1, 1, 0, 0, 0)
>>> string = "24 months"
>>> decrement_datetime_by_string(dt, string)
datetime.datetime(1999, 1, 1, 0, 0)
>>> dt = datetime(2001, 1, 1, 0, 0, 0)
>>> string = "48 months"
>>> decrement_datetime_by_string(dt, string)
datetime.datetime(1997, 1, 1, 0, 0)
>>> dt = datetime(2001, 6, 1, 0, 0, 0)
>>> string = "5 months"
>>> decrement_datetime_by_string(dt, string)
datetime.datetime(2001, 1, 1, 0, 0)
>>> dt = datetime(2001, 6, 1, 0, 0, 0)
>>> string = "7 months"
>>> decrement_datetime_by_string(dt, string)
datetime.datetime(2000, 11, 1, 0, 0)
>>> dt = datetime(2001, 1, 1, 0, 0, 0)
>>> string = "1 year"
>>> decrement_datetime_by_string(dt, string)
datetime.datetime(2000, 1, 1, 0, 0)
:param mydate: A datetime object to incremented
:param increment: A string providing increment information:
The string may include comma separated values of type
seconds, minutes, hours, days, weeks, months and years
Example: Increment the datetime 2001-01-01 00:00:00
with "60 seconds, 4 minutes, 12 hours, 10 days,
1 weeks, 5 months, 1 years" will result in the
datetime 2003-02-18 12:05:00
:param mult: A multiplier, default is 1
:return: The new datetime object or none in case of an error
"""
return modify_datetime_by_string(mydate, increment, mult, sign=int(-1))
###############################################################################
[docs]def increment_datetime_by_string(mydate, increment, mult=1):
"""Return a new datetime object incremented with the provided
relative dates specified as string.
Additional a multiplier can be specified to multiply the increment
before adding to the provided datetime object.
Usage:
.. code-block:: python
>>> dt = datetime(2001, 9, 1, 0, 0, 0)
>>> string = "60 seconds, 4 minutes, 12 hours, 10 days, 1 weeks, 5 months, 1 years"
>>> increment_datetime_by_string(dt, string)
datetime.datetime(2003, 2, 18, 12, 5)
>>> dt = datetime(2001, 11, 1, 0, 0, 0)
>>> string = "1 months"
>>> increment_datetime_by_string(dt, string)
datetime.datetime(2001, 12, 1, 0, 0)
>>> dt = datetime(2001, 11, 1, 0, 0, 0)
>>> string = "13 months"
>>> increment_datetime_by_string(dt, string)
datetime.datetime(2002, 12, 1, 0, 0)
>>> dt = datetime(2001, 1, 1, 0, 0, 0)
>>> string = "72 months"
>>> increment_datetime_by_string(dt, string)
datetime.datetime(2007, 1, 1, 0, 0)
>>> dt = datetime(2001, 1, 1, 0, 0, 0)
>>> string = "72 months"
>>> increment_datetime_by_string(dt, string)
datetime.datetime(2007, 1, 1, 0, 0)
>>> dt = datetime(2001, 1, 1, 0, 0, 0)
>>> string = "5 minutes"
>>> increment_datetime_by_string(dt, string)
datetime.datetime(2001, 1, 1, 0, 5)
>>> dt = datetime(2001, 1, 1, 0, 0, 0)
>>> string = "49 hours"
>>> increment_datetime_by_string(dt, string)
datetime.datetime(2001, 1, 3, 1, 0)
>>> dt = datetime(2001, 1, 1, 0, 0, 0)
>>> string = "3600 seconds"
>>> increment_datetime_by_string(dt, string)
datetime.datetime(2001, 1, 1, 1, 0)
>>> dt = datetime(2001, 1, 1, 0, 0, 0)
>>> string = "30 days"
>>> increment_datetime_by_string(dt, string)
datetime.datetime(2001, 1, 31, 0, 0)
:param mydate: A datetime object to incremented
:param increment: A string providing increment information:
The string may include comma separated values of type
seconds, minutes, hours, days, weeks, months and years
Example: Increment the datetime 2001-01-01 00:00:00
with "60 seconds, 4 minutes, 12 hours, 10 days,
1 weeks, 5 months, 1 years" will result in the
datetime 2003-02-18 12:05:00
:param mult: A multiplier, default is 1
:return: The new datetime object or none in case of an error
"""
return modify_datetime_by_string(mydate, increment, mult, sign=int(1))
###############################################################################
[docs]def modify_datetime_by_string(mydate, increment, mult=1, sign=1):
"""Return a new datetime object incremented with the provided
relative dates specified as string.
Additional a multiplier can be specified to multiply the increment
before adding to the provided datetime object.
:param mydate: A datetime object to incremented
:param increment: A string providing increment information:
The string may include comma separated values of type
seconds, minutes, hours, days, weeks, months and years
Example: Increment the datetime 2001-01-01 00:00:00
with "60 seconds, 4 minutes, 12 hours, 10 days,
1 weeks, 5 months, 1 years" will result in the
datetime 2003-02-18 12:05:00
:param mult: A multiplier, default is 1
:param sign: Choose 1 for positive sign (incrementing) or -1 for
negative sign (decrementing).
:return: The new datetime object or none in case of an error
"""
sign = int(sign)
if sign != 1 and sign != -1:
return None
if increment:
seconds = 0
minutes = 0
hours = 0
days = 0
weeks = 0
months = 0
years = 0
inclist = []
# Split the increment string
incparts = increment.split(",")
for incpart in incparts:
inclist.append(incpart.strip().split(" "))
for inc in inclist:
msgr = get_tgis_message_interface()
if len(inc) < 2:
msgr.error(_("Wrong increment format: %s") % (increment))
return None
if inc[1].find("seconds") >= 0 or inc[1].find("second") >= 0:
seconds = sign * mult * int(inc[0])
elif inc[1].find("minutes") >= 0 or inc[1].find("minute") >= 0:
minutes = sign * mult * int(inc[0])
elif inc[1].find("hours") >= 0 or inc[1].find("hour") >= 0:
hours = sign * mult * int(inc[0])
elif inc[1].find("days") >= 0 or inc[1].find("day") >= 0:
days = sign * mult * int(inc[0])
elif inc[1].find("weeks") >= 0 or inc[1].find("week") >= 0:
weeks = sign * mult * int(inc[0])
elif inc[1].find("months") >= 0 or inc[1].find("month") >= 0:
months = sign * mult * int(inc[0])
elif inc[1].find("years") >= 0 or inc[1].find("year") >= 0:
years = sign * mult * int(inc[0])
else:
msgr.error(_("Wrong increment format: %s") % (increment))
return None
return modify_datetime(mydate, years, months, weeks, days, hours,
minutes, seconds)
return mydate
###############################################################################
[docs]def modify_datetime(mydate, years=0, months=0, weeks=0, days=0, hours=0,
minutes=0, seconds=0):
"""Return a new datetime object incremented with the provided
relative dates and times"""
tdelta_seconds = timedelta(seconds=seconds)
tdelta_minutes = timedelta(minutes=minutes)
tdelta_hours = timedelta(hours=hours)
tdelta_days = timedelta(days=days)
tdelta_weeks = timedelta(weeks=weeks)
tdelta_months = timedelta(0)
tdelta_years = timedelta(0)
if months > 0:
# Compute the actual number of days in the month to add as timedelta
year = mydate.year
month = mydate.month
all_months = int(months) + int(month)
years_to_add = int(all_months / 12.001)
residual_months = all_months - (years_to_add * 12)
# Make a deep copy of the datetime object
dt1 = copy.copy(mydate)
# Make sure the month starts with a 1
if residual_months == 0:
residual_months = 1
try:
dt1 = dt1.replace(year=year + years_to_add, month=residual_months)
except:
raise
tdelta_months = dt1 - mydate
elif months < 0:
# Compute the actual number of days in the month to add as timedelta
year = mydate.year
month = mydate.month
years_to_remove = 0
all_months = int(months) + int(month)
if all_months <= 0:
years_to_remove = abs(int(all_months / 12.001))
residual_months = all_months + (years_to_remove * 12)
years_to_remove += 1
else:
residual_months = all_months
# Make a deep copy of the datetime object
dt1 = copy.copy(mydate)
# Correct the months
if residual_months <= 0:
residual_months += 12
try:
dt1 = dt1.replace(year=year - years_to_remove,
month=residual_months)
except:
raise
tdelta_months = dt1 - mydate
if years != 0:
# Make a deep copy of the datetime object
dt1 = copy.copy(mydate)
# Compute the number of days
dt1 = dt1.replace(year=mydate.year + int(years))
tdelta_years = dt1 - mydate
return mydate + tdelta_seconds + tdelta_minutes + tdelta_hours + \
tdelta_days + tdelta_weeks + tdelta_months + tdelta_years
###############################################################################
[docs]def adjust_datetime_to_granularity(mydate, granularity):
"""Modify the datetime object to fit the given granularity
- Years will start at the first of Januar
- Months will start at the first day of the month
- Days will start at the first Hour of the day
- Hours will start at the first minute of an hour
- Minutes will start at the first second of a minute
Usage:
.. code-block:: python
>>> dt = datetime(2001, 8, 8, 12,30,30)
>>> adjust_datetime_to_granularity(dt, "5 seconds")
datetime.datetime(2001, 8, 8, 12, 30, 30)
>>> adjust_datetime_to_granularity(dt, "20 minutes")
datetime.datetime(2001, 8, 8, 12, 30)
>>> adjust_datetime_to_granularity(dt, "20 minutes")
datetime.datetime(2001, 8, 8, 12, 30)
>>> adjust_datetime_to_granularity(dt, "3 hours")
datetime.datetime(2001, 8, 8, 12, 0)
>>> adjust_datetime_to_granularity(dt, "5 days")
datetime.datetime(2001, 8, 8, 0, 0)
>>> adjust_datetime_to_granularity(dt, "2 weeks")
datetime.datetime(2001, 8, 6, 0, 0)
>>> adjust_datetime_to_granularity(dt, "6 months")
datetime.datetime(2001, 8, 1, 0, 0)
>>> adjust_datetime_to_granularity(dt, "2 years")
datetime.datetime(2001, 1, 1, 0, 0)
>>> adjust_datetime_to_granularity(dt, "2 years, 3 months, 5 days, 3 hours, 3 minutes, 2 seconds")
datetime.datetime(2001, 8, 8, 12, 30, 30)
>>> adjust_datetime_to_granularity(dt, "3 months, 5 days, 3 minutes")
datetime.datetime(2001, 8, 8, 12, 30)
>>> adjust_datetime_to_granularity(dt, "3 weeks, 5 days")
datetime.datetime(2001, 8, 8, 0, 0)
"""
if granularity:
has_seconds = False
has_minutes = False
has_hours = False
has_days = False
has_weeks = False
has_months = False
has_years = False
seconds = mydate.second
minutes = mydate.minute
hours = mydate.hour
days = mydate.day
weekday = mydate.weekday()
months = mydate.month
years = mydate.year
granlist = []
# Split the increment string
granparts = granularity.split(",")
for granpart in granparts:
granlist.append(granpart.strip().split(" "))
for inc in granlist:
if inc[1].find("seconds") >= 0 or inc[1].find("second") >= 0:
has_seconds = True
elif inc[1].find("minutes") >= 0 or inc[1].find("minute") >= 0:
has_minutes = True
elif inc[1].find("hours") >= 0 or inc[1].find("hour") >= 0:
has_hours = True
elif inc[1].find("days") >= 0 or inc[1].find("day") >= 0:
has_days = True
elif inc[1].find("weeks") >= 0 or inc[1].find("week") >= 0:
has_weeks = True
elif inc[1].find("months") >= 0 or inc[1].find("month") >= 0:
has_months = True
elif inc[1].find("years") >= 0 or inc[1].find("year") >= 0:
has_years = True
else:
msgr = get_tgis_message_interface()
msgr.error(_("Wrong granularity format: %s") % (granularity))
return None
if has_seconds:
pass
elif has_minutes: # Start at 0 seconds
seconds = 0
elif has_hours: # Start at 0 minutes and seconds
seconds = 0
minutes = 0
elif has_days: # Start at 0 hours, minutes and seconds
seconds = 0
minutes = 0
hours = 0
elif has_weeks: # Start at the first day of the week (Monday) at 00:00:00
seconds = 0
minutes = 0
hours = 0
if days > weekday:
days = days - weekday # this needs to be fixed
else:
days = days + weekday # this needs to be fixed
elif has_months: # Start at the first day of the month at 00:00:00
seconds = 0
minutes = 0
hours = 0
days = 1
elif has_years: # Start at the first day of the first month at 00:00:00
seconds = 0
minutes = 0
hours = 0
days = 1
months = 1
dt = copy.copy(mydate)
return dt.replace(year=years, month=months, day=days,
hour=hours, minute=minutes, second=seconds)
###############################################################################
[docs]def compute_datetime_delta(start, end):
"""Return a dictionary with the accumulated delta in year, month, day,
hour, minute and second
Usage:
.. code-block:: python
>>> start = datetime(2001, 1, 1, 00,00,00)
>>> end = datetime(2001, 1, 1, 00,00,00)
>>> compute_datetime_delta(start, end)
{'hour': 0, 'month': 0, 'second': 0, 'max_days': 0, 'year': 0, 'day': 0, 'minute': 0}
>>> start = datetime(2001, 1, 1, 00,00,14)
>>> end = datetime(2001, 1, 1, 00,00,44)
>>> compute_datetime_delta(start, end)
{'hour': 0, 'month': 0, 'second': 30, 'max_days': 0, 'year': 0, 'day': 0, 'minute': 0}
>>> start = datetime(2001, 1, 1, 00,00,44)
>>> end = datetime(2001, 1, 1, 00,01,14)
>>> compute_datetime_delta(start, end)
{'hour': 0, 'month': 0, 'second': 30, 'max_days': 0, 'year': 0, 'day': 0, 'minute': 1}
>>> start = datetime(2001, 1, 1, 00,00,30)
>>> end = datetime(2001, 1, 1, 00,05,30)
>>> compute_datetime_delta(start, end)
{'hour': 0, 'month': 0, 'second': 300, 'max_days': 0, 'year': 0, 'day': 0, 'minute': 5}
>>> start = datetime(2001, 1, 1, 00,00,00)
>>> end = datetime(2001, 1, 1, 00,01,00)
>>> compute_datetime_delta(start, end)
{'hour': 0, 'month': 0, 'second': 0, 'max_days': 0, 'year': 0, 'day': 0, 'minute': 1}
>>> start = datetime(2011,10,31, 00,45,00)
>>> end = datetime(2011,10,31, 01,45,00)
>>> compute_datetime_delta(start, end)
{'hour': 1, 'second': 0, 'max_days': 0, 'year': 0, 'day': 0, 'minute': 60}
>>> start = datetime(2011,10,31, 00,45,00)
>>> end = datetime(2011,10,31, 01,15,00)
>>> compute_datetime_delta(start, end)
{'hour': 1, 'second': 0, 'max_days': 0, 'year': 0, 'day': 0, 'minute': 30}
>>> start = datetime(2011,10,31, 00,45,00)
>>> end = datetime(2011,10,31, 12,15,00)
>>> compute_datetime_delta(start, end)
{'hour': 12, 'second': 0, 'max_days': 0, 'year': 0, 'day': 0, 'minute': 690}
>>> start = datetime(2011,10,31, 00,00,00)
>>> end = datetime(2011,10,31, 01,00,00)
>>> compute_datetime_delta(start, end)
{'hour': 1, 'second': 0, 'max_days': 0, 'year': 0, 'day': 0, 'minute': 0}
>>> start = datetime(2011,10,31, 00,00,00)
>>> end = datetime(2011,11,01, 01,00,00)
>>> compute_datetime_delta(start, end)
{'hour': 25, 'second': 0, 'max_days': 1, 'year': 0, 'day': 1, 'minute': 0}
>>> start = datetime(2011,10,31, 12,00,00)
>>> end = datetime(2011,11,01, 06,00,00)
>>> compute_datetime_delta(start, end)
{'hour': 18, 'second': 0, 'max_days': 0, 'year': 0, 'day': 0, 'minute': 0}
>>> start = datetime(2011,11,01, 00,00,00)
>>> end = datetime(2011,12,01, 01,00,00)
>>> compute_datetime_delta(start, end)
{'hour': 721, 'month': 1, 'second': 0, 'max_days': 30, 'year': 0, 'day': 0, 'minute': 0}
>>> start = datetime(2011,11,01, 00,00,00)
>>> end = datetime(2011,11,05, 00,00,00)
>>> compute_datetime_delta(start, end)
{'hour': 0, 'second': 0, 'max_days': 4, 'year': 0, 'day': 4, 'minute': 0}
>>> start = datetime(2011,10,06, 00,00,00)
>>> end = datetime(2011,11,05, 00,00,00)
>>> compute_datetime_delta(start, end)
{'hour': 0, 'second': 0, 'max_days': 30, 'year': 0, 'day': 30, 'minute': 0}
>>> start = datetime(2011,12,02, 00,00,00)
>>> end = datetime(2012,01,01, 00,00,00)
>>> compute_datetime_delta(start, end)
{'hour': 0, 'second': 0, 'max_days': 30, 'year': 1, 'day': 30, 'minute': 0}
>>> start = datetime(2011,01,01, 00,00,00)
>>> end = datetime(2011,02,01, 00,00,00)
>>> compute_datetime_delta(start, end)
{'hour': 0, 'month': 1, 'second': 0, 'max_days': 31, 'year': 0, 'day': 0, 'minute': 0}
>>> start = datetime(2011,12,01, 00,00,00)
>>> end = datetime(2012,01,01, 00,00,00)
>>> compute_datetime_delta(start, end)
{'hour': 0, 'month': 1, 'second': 0, 'max_days': 31, 'year': 1, 'day': 0, 'minute': 0}
>>> start = datetime(2011,12,01, 00,00,00)
>>> end = datetime(2012,06,01, 00,00,00)
>>> compute_datetime_delta(start, end)
{'hour': 0, 'month': 6, 'second': 0, 'max_days': 183, 'year': 1, 'day': 0, 'minute': 0}
>>> start = datetime(2011,06,01, 00,00,00)
>>> end = datetime(2021,06,01, 00,00,00)
>>> compute_datetime_delta(start, end)
{'hour': 0, 'month': 120, 'second': 0, 'max_days': 3653, 'year': 10, 'day': 0, 'minute': 0}
>>> start = datetime(2011,06,01, 00,00,00)
>>> end = datetime(2012,06,01, 12,00,00)
>>> compute_datetime_delta(start, end)
{'hour': 8796, 'month': 12, 'second': 0, 'max_days': 366, 'year': 1, 'day': 0, 'minute': 0}
>>> start = datetime(2011,06,01, 00,00,00)
>>> end = datetime(2012,06,01, 12,30,00)
>>> compute_datetime_delta(start, end)
{'hour': 8796, 'month': 12, 'second': 0, 'max_days': 366, 'year': 1, 'day': 0, 'minute': 527790}
>>> start = datetime(2011,06,01, 00,00,00)
>>> end = datetime(2012,06,01, 12,00,05)
>>> compute_datetime_delta(start, end)
{'hour': 8796, 'month': 12, 'second': 31665605, 'max_days': 366, 'year': 1, 'day': 0, 'minute': 0}
>>> start = datetime(2011,06,01, 00,00,00)
>>> end = datetime(2012,06,01, 00,30,00)
>>> compute_datetime_delta(start, end)
{'hour': 0, 'month': 12, 'second': 0, 'max_days': 366, 'year': 1, 'day': 0, 'minute': 527070}
>>> start = datetime(2011,06,01, 00,00,00)
>>> end = datetime(2012,06,01, 00,00,05)
>>> compute_datetime_delta(start, end)
{'hour': 0, 'month': 12, 'second': 31622405, 'max_days': 366, 'year': 1, 'day': 0, 'minute': 0}
:return: A dictionary with year, month, day, hour, minute and second as
keys()
"""
comp = {}
day_diff = (end - start).days
comp["max_days"] = day_diff
# Date
# Count full years
d = end.year - start.year
comp["year"] = d
# Count full months
if start.month == 1 and end.month == 1:
comp["month"] = 0
elif start.day == 1 and end.day == 1:
d = end.month - start.month
if d < 0:
d = d + 12 * comp["year"]
elif d == 0:
d = 12 * comp["year"]
comp["month"] = d
# Count full days
if start.day == 1 and end.day == 1:
comp["day"] = 0
else:
comp["day"] = day_diff
# Time
# Hours
if start.hour == 0 and end.hour == 0:
comp["hour"] = 0
else:
d = end.hour - start.hour
if d < 0:
d = d + 24 + 24 * day_diff
else:
d = d + 24 * day_diff
comp["hour"] = d
# Minutes
if start.minute == 0 and end.minute == 0:
comp["minute"] = 0
else:
d = end.minute - start.minute
if d != 0:
if comp["hour"]:
d = d + 60 * comp["hour"]
else:
d = d + 24 * 60 * day_diff
elif d == 0:
if comp["hour"]:
d = 60 * comp["hour"]
else:
d = 24 * 60 * day_diff
comp["minute"] = d
# Seconds
if start.second == 0 and end.second == 0:
comp["second"] = 0
else:
d = end.second - start.second
if d != 0:
if comp["minute"]:
d = d + 60 * comp["minute"]
elif comp["hour"]:
d = d + 3600 * comp["hour"]
else:
d = d + 24 * 60 * 60 * day_diff
elif d == 0:
if comp["minute"]:
d = 60 * comp["minute"]
elif comp["hour"]:
d = 3600 * comp["hour"]
else:
d = 24 * 60 * 60 * day_diff
comp["second"] = d
return comp
###############################################################################
[docs]def check_datetime_string(time_string):
"""Check if a string can be converted into a datetime object
Supported ISO string formats are:
- YYYY-mm-dd
- YYYY-mm-dd HH:MM:SS
Time zones are not supported
:param time_string: The time string to be checked for conversion
:return: datetime: object or an error message string in case of an error
"""
global has_dateutil
if has_dateutil:
# First check if there is only a single number, which specifies
# relative time. dateutil will interprete a single number as a valid
# time string, so we have to catch this case beforehand
try:
value = int(time_string)
return _("Time string seems to specify relative time")
except ValueError:
pass
try:
time_object = parser.parse(time_string)
except Exception as inst:
time_object = str(inst)
return time_object
# BC is not supported
if time_string.find("bc") > 0:
return _("Dates Before Christ (BC) are not supported")
# BC is not supported
if time_string.find("+") > 0:
return _("Time zones are not supported")
if time_string.find(":") > 0:
time_format = "%Y-%m-%d %H:%M:%S"
else:
time_format = "%Y-%m-%d"
try:
return datetime.strptime(time_string, time_format)
except:
return _("Unable to parse time string: %s" % time_string)
###############################################################################
[docs]def string_to_datetime(time_string):
"""Convert a string into a datetime object
In case datutil is not installed the supported ISO string formats are:
- YYYY-mm-dd
- YYYY-mm-dd HH:MM:SS
- Time zones are not supported
If dateutil is installed, all string formats of the dateutil module
are supported, as well as time zones
:param time_string: The time string to convert
:return: datetime object or None in case the string
could not be converted
"""
if not isinstance(time_string, str):
return None
time_object = check_datetime_string(time_string)
if not isinstance(time_object, datetime):
msgr = get_tgis_message_interface()
msgr.error(str(time_object))
return None
return time_object
###############################################################################
[docs]def datetime_to_grass_datetime_string(dt):
"""Convert a python datetime object into a GRASS datetime string
.. code-block:: python
>>> import grass.temporal as tgis
>>> import dateutil.parser as parser
>>> dt = parser.parse("2011-01-01 10:00:00 +01:30")
>>> tgis.datetime_to_grass_datetime_string(dt)
'01 jan 2011 10:00:00 +0090'
>>> dt = parser.parse("2011-01-01 10:00:00 +02:30")
>>> tgis.datetime_to_grass_datetime_string(dt)
'01 jan 2011 10:00:00 +0150'
>>> dt = parser.parse("2011-01-01 10:00:00 +12:00")
>>> tgis.datetime_to_grass_datetime_string(dt)
'01 jan 2011 10:00:00 +0720'
>>> dt = parser.parse("2011-01-01 10:00:00 -01:30")
>>> tgis.datetime_to_grass_datetime_string(dt)
'01 jan 2011 10:00:00 -0090'
"""
# GRASS datetime month names
month_names = ["", "jan", "feb", "mar", "apr", "may", "jun",
"jul", "aug", "sep", "oct", "nov", "dec"]
# Check for time zone info in the datetime object
if dt.tzinfo is not None:
tz = dt.tzinfo.utcoffset(0)
if tz.seconds > 86400 / 2:
tz = (tz.seconds - 86400) / 60
else:
tz = tz.seconds/60
string = "%.2i %s %.2i %.2i:%.2i:%.2i %+.4i" % (dt.day,
month_names[dt.month],
dt.year, dt.hour,
dt.minute, dt.second,
tz)
else:
string = "%.2i %s %.4i %.2i:%.2i:%.2i" % (dt.day, month_names[
dt.month], dt.year, dt.hour, dt.minute, dt.second)
return string
###############################################################################
suffix_units = {"years": "%Y",
"year": "%Y",
"months": "%Y_%m",
"month": "%Y_%m",
"weeks": "%Y_%m_%d",
"week": "%Y_%m_%d",
"days": "%Y_%m_%d",
"day": "%Y_%m_%d",
"hours": "%Y_%m_%d_%H",
"hour": "%Y_%m_%d_%H",
"minutes": "%Y_%m_%d_%H_%M",
"minute": "%Y_%m_%d_%H_%M"}
[docs]def create_suffix_from_datetime(start_time, granularity):
"""Create a datetime string based on a datetime object and a provided
granularity that can be used as suffix for map names.
dateteime=2001-01-01 00:00:00, granularity="1 month" returns "2001_01"
:param start_time: The datetime object
:param granularity: The granularity for example "1 month" or "100 seconds"
:return: A string
"""
global suffix_units
return start_time.strftime(suffix_units[granularity.split(' ')[1]])
if __name__ == "__main__":
import doctest
doctest.testmod()
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