Source code for utils.timeUtils
# Copyright (C) 2012 VT SuperDARN Lab
# Full license can be found in LICENSE.txt
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
"""
.. module:: timeUtils
:synopsis: A module for manipulating time representations
.. moduleauthor:: VTSD Lab
****************************
**Module**: utils.timeUtils
****************************
**Functions**:
* :func:`utils.timeUtils.dateToDecYear`
* :func:`utils.timeUtils.dateToYyyymmdd`
* :func:`utils.timeUtils.datetimeToEpoch`
* :func:`utils.timeUtils.julToDatetime`
* :func:`utils.timeUtils.parseDate`
* :func:`utils.timeUtils.parseTime`
* :func:`utils.timeUtils.timeYrsecToDate`
* :func:`utils.timeUtils.yyyymmddToDate`
"""
[docs]def dateToYyyymmdd(myDate):
"""takes a python datetime object and returns a string in yyyymmdd format
**Args**:
* **myDate** (`datetime <http://tinyurl.com/bl352yx>`_): a python datetime object
**Returns**:
* **dateStr** (str): a string in yyyymmdd format
**Example**:
::
import datetime as dt
dateStr = utils.timeUtils.dateToYyyymmdd(dt.datetime(2012,7,10))
Written by AJ 20120718
"""
from datetime import datetime
if isinstance(myDate,datetime):
dateStr = ''
#create year string
yr = myDate.year
if(yr < 10):
dateStr += '000'+str(yr)
elif(yr < 100):
dateStr += '00'+str(yr)
elif(yr < 1000):
dateStr += '0'+str(yr)
else:
dateStr += str(yr)
#create month string
mon = myDate.month
if(mon < 10):
dateStr += '0'+str(mon)
else:
dateStr += str(mon)
#create day string
day = myDate.day
if(day < 10):
dateStr += '0'+str(day)
else:
dateStr += str(day)
#return everything together
return dateStr
else:
print 'error, input must be type datetime'
sys.exit()
[docs]def yyyymmddToDate(dateStr):
"""takes a string in yyyymmdd format and returns a python date object
**Args**:
* **dateStr** (str): a string in yyyymmdd format
**Returns**:
* **myDate** (`datetime <http://tinyurl.com/bl352yx>`_): a python datetime object
**Example**:
::
myDate = utils.timeUtils.yyyymmddToDate('20120710')
Written by AJ 20120718
"""
from datetime import datetime
import sys
#check input type
if isinstance(dateStr,str):
#try to make the date object
try:
return datetime(int(dateStr[0:4]),int(dateStr[4:6]),int(dateStr[6:8]))
#if there was a problem with the input
except:
print 'error in input '+dateStr
sys.exit()
else:
print 'error, input must be a string'
sys.exit()
[docs]def timeYrsecToDate(yrsec, year):
"""Converts time expressed in seconds from start of year to a python DATETIME object
**Args**:
* **yrsec** (int): seconds since start of year
* **year** (int): year in YYYY
**Returns**:
* **myDate** (`datetime <http://tinyurl.com/bl352yx>`_): a python DATETIME object.
**Example**:
::
myDate = utils.timeUtils.timeYrsecToDate(1205304,2012)
Written by Sebastien, Jul. 2012
"""
from datetime import datetime
from datetime import timedelta
if year >= 2038:
print 'timeYrsecToDate: Year {:d} out of range: forcing 2038'.format(year)
year = 2038
myDate = datetime(year, 1, 1) + timedelta(seconds = yrsec)
return myDate
[docs]def julToDatetime( ndarray ) :
"""Convert a julian date to a datetime object.
**Args**:
* **NDARRAY** (float or list): single float64 or a numpy array of Julian Dates.
**Returns**:
* **dt** (list): list of datetime objects
**Example**:
::
myDateList = utils.timeUtils.julToDatetime(2456118.5)
Created by Nathaniel Frissell 20120810
"""
import datetime
import dateutil.parser
import numpy
import spacepy.time as spt
t = spt.Ticktock(ndarray,'JD')
dt = list()
for iso in t.ISO: dt.append(dateutil.parser.parse(iso))
return dt
[docs]def datetimeToEpoch(myDate):
"""reads in a datetime and outputs the equivalent epoch time
**Args**:
* **myDate** (`datetime <http://tinyurl.com/bl352yx>`_): a datetime object
**Returns**:
* **myEpoch** (float): an epoch time equal to the datetime object
**Example**
::
import datetime as dt
epoch = utils.timeUtils.datetimeToEpoch(dt.datetime(2012,7,10))
Written by AJ 20120914
Modified by Nathaniel Frissell 20130729 - Added list support.
"""
import numpy
import time
if numpy.size(myDate) == 1:
unx = time.mktime(myDate.timetuple())
else:
unx = [time.mktime(dt.timetuple()) for dt in myDate]
return unx
[docs]def dateToDecYear(date):
"""Convert (`datetime <http://tinyurl.com/bl352yx>`_) object to decimal year
**Args**:
* **date** (`datetime <http://tinyurl.com/bl352yx>`_): date and time
**Returns**:
* **dyear** (float): decimal year
**Example**
::
import datetime as dt
decYr = utils.timeUtils.dateToDecYear(dt.datetime(2012,7,10))
written by Sebastien, 2013-02
"""
from datetime import datetime as dt
import time
# returns seconds since epoch
sE = lambda date: time.mktime(date.timetuple())
year = date.year
startOfThisYear = dt(year=year, month=1, day=1)
startOfNextYear = dt(year=year+1, month=1, day=1)
yearElapsed = sE(date) - sE(startOfThisYear)
yearDuration = sE(startOfNextYear) - sE(startOfThisYear)
fraction = yearElapsed/yearDuration
return date.year + fraction
[docs]def parseDate( date ) :
""" Parse YYYYMMDD dates in YYYY, MM, DD and vice versa
**Args**:
* **date** (str or list): experiment date in YYYYMMDD or [YYYY,MM,DD]
**Returns**:
* **tdate** (list or int): experiment date in [YYYY,MM,DD] or YYYYMMDD
**Example**:
::
tlist = utils.timeUtils.parseDate('20120710')
ttime = utils.timeUtils.parseDate([2012,07,10])
Created by Sebastien
"""
# transform date into an array for testing
if not isinstance(date, list): date = [date]
# make sure we are getting integers
for id in range( len(date) ):
if isinstance(date[id], str): date[id] = int(date[id])
# parse date one way or another
if len(date) == 3:
tdate = date[0]*10000 + date[1]*100 + date[2]
elif len(date) == 1:
tdate = [date[0]/10000, date[0]/100-date[0]/10000*100, date[0]-date[0]/100*100]
else:
print 'Invalid date format: ', date
return
return tdate
[docs]def parseTime( time ) :
""" Parse HHMM or HHMMSS dates in HH, MM, SS and vice versa
**Args**:
* **TIME** (str or list): time in HHMM or HHMMSS OR [HH,MM] or [HH,MM,SS]
**Returns**
* **ttime** (list or int): time in [HH,MM] or [HH,MM,SS] OR HHMM or HHMMSS
**Example**:
::
tlist = utils.timeUtils.parseDate('065022')
tstr = utils.timeUtils.parseDate([6,50,22])
Created by Sebastien
"""
# transform time into an array for testing
if not isinstance(time, list): time = [time]
# make sure we are getting integers
for it in range( len(time) ):
if isinstance(time[it], str): time[it] = int(time[it])
# parse time one way or another
if len(time) == 3:
ttime = time[0]*10000 + time[1]*100 + time[2]
elif len(time) == 2:
ttime = time[0]*100 + time[1]
elif len(time) == 1 and len(str(time[0])) > 4 and len(str(time[0])) <= 6:
ttime = [time[0]/10000, time[0]/100-time[0]/10000*100, time[0]-time[0]/100*100]
elif len(time) == 1 and len(str(time[0])) >=1 and len(str(time[0])) <= 4:
ttime = [time[0]/100, time[0]-time[0]/100*100]
else:
print 'Invalid time format: ', time
return
return ttime
