topic Re: Calculate Date Field. in Python Questions

Calculate Date Field.

jaykapalczynski — Tue, 04 Oct 2016 18:52:50 GMT

I am trying to calculate a date/time field in Python with not much luck...

In ArcGIS I am doing this with a calculate and it calculates fine...its going into a Date Field.

(Right("00" & [Hour],2) + ":" + Right("00" & [Minute],2))

result: 4:02:00 PM

I want to do this in Python and am trying this after reading in a CSV File. No error but no result in the feature class created.

If I dont get the syntax correct it tells me "Right" is not defined

Hour = str(lineSplit[3])
Minute = str(lineSplit[4])

CalcDate1 = "Right('00' & Hour,2) & ':' & Right('00' & Minute,2)"
print CalcDate1

It gives me this in the results window in the shell:

Right('00' & Hour,2) & ':' & Right('00' & Minute,2)

Re: Calculate Date Field.

MitchHolley1 — Tue, 04 Oct 2016 19:01:26 GMT

So, are you trying to read through the CSV and get the date from different fields? Can you show the fields?

Re: Calculate Date Field.

jaykapalczynski — Tue, 04 Oct 2016 19:04:26 GMT

Yes as I parse the CSV I set the Hour and Minute to Variables...

Hour Minute

16 2

This results in 4:02:00 PM when I run it in ArcGIS with the formula above.

Re: Calculate Date Field.

jaykapalczynski — Tue, 04 Oct 2016 19:41:46 GMT

This is how I am going through the CSV and assigning the variables for each record....I then write to the Feature Class.

for ln in open (r"C:\Users\tjv36463\Desktop\Bear Collar\rangedate_D032495_20160822124736_NH.txt", 'r').readlines():
lineSplit = ln.split(",")

Hour = int(lineSplit[3])
Minute = int(lineSplit[4])

CalcDate1 = Right('00' & Hour,2) & ':' & Right('00' & Minute,2)

In ArcGIS using calculate on a date field with this: Right('00' & [Hour],2) & ':' & Right('00' & [Minute],2) I get this: 4:00:00 PM it the Values were 16 for hour and 2 for Minute

Just need to translate this to Python

Edit: Looks like ArcGIS is converting the Military time to normal time....think I need to add this into Python or is there a date handler of some sort to do that conversion?

Re: Calculate Date Field.

DarrenWiens2 — Sun, 12 Dec 2021 05:44:35 GMT

think I need to add this into Python or is there a date handler of some sort to do that conversion?

Yes, the normal way to deal with date/time in Python is via datetime.

e.g.

Expression:

getdate( !Hour! , !Minute! )‍‍

Codeblock:

import datetime
def getdate(hour, minute):
 return datetime.datetime.strptime(str(hour).zfill(2) + ' ' + str(minute).zfill(2), '%H %M')‍‍‍‍‍‍

Result:

Re: Calculate Date Field.

DanPatterson_Retired — Sun, 12 Dec 2021 05:44:37 GMT

Notes and references Messing with dates and time

Notes:
: - http://www.iso.org/iso/support/faqs/faqs_widely_used_standards/
: widely_used_standards_other/iso8601
: - http://strftime.org
: - Richard Fairhurst's blog
: https://community.esri.com/blogs/richard_fairhurst/2016/07/01/
: ive-saved-time-in-a-bottle-how-do-i-get-it-back-out-doing-more-
: with-date-fields-using-the-field-calculator-and-python
: - https://pymotw.com/3/datetime/
: The default string representation of a datetime object uses the ISO-8601
: format (YYYY-MM-DDTHH:MM:SS.mmmmmm). Alternate formats can be generated
: using strftime().

windows 3.x 2.7 from Richards
yy or y = %y (Year number without century with or without a leading zero)
yyyy = %Y (Year number with century)
MM or M = %m (Month number with or without a leading zero)
MMM = %b (Month as locale’s abbreviated name)
MMMM = %B (Month as locale’s full name)
dd or d = %d (Day of the month number with or without a leading zero)
ddd = %a (Weekday as locale’s abbreviated name)
dddd = %A (Weekday as locale’s full name)

hh or h = %I (Hour (12-hour clock) with or without a leading zero)
HH or H = %H (Hour (24-hour clock) with or without a leading zero)
mm or m = %M (Minute number with or without a leading zero)
ss or s = %S (Second number with or without a leading zero)
tt = %p (Locale’s equivalent of either AM or PM)
/, -, : = /, -, : (literal date or time separator characters)

Test output... fiddle with the options above to get what you want

def _demo():
    """   
    :Required:
    :--------
    :  import datetime
    :Returns
    :-------
    :
    """
    today = datetime.datetime.today()
    print('ISO     :', today)
    print('format(): {:%a %b %d %H:%M:%S %Y}'.format(today))
    return today
    

if __name__=="__main__":
    """   """
    #print("Script... {}".format(script))
    a  = _demo()‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

sample output.... change line 12 to get what you want

ISO     : 2016-10-04 17:06:34.598792
format(): Tue Oct 04 17:06:34 2016‍‍

Re: Calculate Date Field.

jaykapalczynski — Wed, 05 Oct 2016 00:01:41 GMT

Think I got it....one second...

1. I still get military time and missing the AM PM

2. Only looking for the time not the date on the front...

Not really....did this and got this..but getting closer...

If I use this I get error: getDateTime = getdate(!Hour!, !Minute!)

RESULT:

1900-01-01 20:01:00
1900-01-01 00:01:00
1900-01-01 04:01:00
1900-01-01 12:02:00
1900-01-01 16:01:00
1900-01-01 20:01:00

CODE:

import arcpy
import datetime

def getdate(hour, minute):
return datetime.datetime.strptime(str(Hour).zfill(2) + ' ' + str(Minute).zfill(2), '%H %M')

fc = r'C:\Users\tjv36463\Desktop\Bear Collar\BearLocationImports.gdb\BearCollar'

cursor = arcpy.da.InsertCursor (fc,["CollarSeri", "Year", "Julianday", "Hour", "Minute", "Activity", "Temperatur", "Latitude", "Longitude", "HDOP", "NumSats", "FixTime", "Date", "_2D_3D", "BearID", "SHAPE@XY"])

for ln in open (r"C:\Users\tjv36463\Desktop\Bear Collar\rangedate_D032495_20160822124736_NH.txt", 'r').readlines():

lineSplit = ln.split(",")

Hour = int(lineSplit[3])
Minute = int(lineSplit[4])

getDateTime = getdate(Hour, Minute)
print getDateTime

Re: Calculate Date Field.

DarrenWiens2 — Wed, 05 Oct 2016 00:11:24 GMT

Did you import datetime? Otherwise, what's the full error message?

Re: Calculate Date Field.

DarrenWiens2 — Wed, 05 Oct 2016 00:28:03 GMT

I think the difference you're seeing between my example and yours, is that I'm writing the datetime object to a geodatabase date field through the field calculator and you're printing the datetime object directly.

From Fundamentals of date fields—Help | ArcGIS for Desktop: "A geodatabase formats the date as datetime yyyy-mm-dd hh:mm:ss AM or PM." So, no matter in which date format Python or my system settings would like to display the datetime object, once it's written to the geodatabase date field, it will be yyyy-mm-dd hh:mm:ss AM or PM.

Since you're printing the raw datetime object, it's either the Python datetime object itself or your system time settings that control what format it displays in the print output.

Regarding time only format, you will have to format the datetime object into a string using strftime(), and write it to a string type field (won't work in date type field).

Re: Calculate Date Field.

jaykapalczynski — Wed, 05 Oct 2016 00:40:42 GMT

When I use my example above why do I still get military time and no AM PM...I can deal with the date at the front...just want the time to at least come out right.

Im gonna write this to a GDB field and see if it differs....

THANKS for you help....very much appreciated.

Re: Calculate Date Field.

jaykapalczynski — Wed, 05 Oct 2016 00:46:22 GMT

That did it....when I wrote to my GDB field it was in normal time and had the AM PM on it....with my lack of knowledge here I think I might just strip the characters(Date) from the front of the variable and try that....I hate dates....

Unless you have an example of the .strftime

Re: Calculate Date Field.

jaykapalczynski — Wed, 05 Oct 2016 00:55:48 GMT

If I could get that one last step to only time I would be done...I cant thank you enough for this help...newbee is very grateful.

Re: Calculate Date Field.

jaykapalczynski — Wed, 05 Oct 2016 01:03:30 GMT

I did it like this but dont think this is the best way....

getDateTime = getdate(Hour, Minute)
getDateTime2 = str(getDateTime)
getDateTime3 = getDateTime2[-8:]

# send getDateTime3 to the insert....came out alright...but lots of processing....

Re: Calculate Date Field.

DarrenWiens2 — Sun, 12 Dec 2021 05:44:40 GMT

Yeah, I hate dates, too. I've gotten by only using the final section of the datetime help page, where it explains strptime (converts string to datetime), strftime (converts datetime to string), and the date formatting codes.

import datetime 
my_string = '7:30AM March 15, 2000' # some date
dt = datetime.datetime.strptime(my_string, '%H:%M%p %B %d, %Y') # create datetime object from string
my_new_string = dt.strftime('%H-----%M') # create a string from some parts of the datetime object
print my_new_string‍‍‍‍‍‍‍‍‍‍

Result:

07-----30‍‍

Some things I think about (whether they're wrong or right):

- the datetime object is sort of formatless, but has all formats available through strftime (I suspect the format is defined in the help)

- datetime objects are very smart when it comes to date operations (like "what is the time 2074 minutes from 9:00pm on Friday, June 29?")

- those date formatting codes are important, and that's how you pull out the time components of the datetime object via strftime()

Re: Calculate Date Field.

jaykapalczynski — Wed, 05 Oct 2016 01:29:12 GMT

Mitch Holley, Darren Wiens THANK YOU FOR YOUR HELP AND SUPPORT....Things are running great...although not the most efficient way but I got it...with YOUR help of course

ANY QUESTIONS: please feel free to reply and I will get back with you..

THANKS Again Mitch and Darren....SOOOO very much appreciated.

1. Read CSV to file to get all records

2. I calculated the Time field (CalcTime) from an Hour and Minute Field..

12:02:00 AM

3. Once I had that I calculated the Full CalcDateTime field from CalcTime above and the Date field from the CSV

6/29/2016 12:02:00 AM

4. Inserted ROWS into the Feature Class using SHAPE@XY Token to create the geometry

Hour Minute from CSV File

0 2

getTime3 Variable - CalcTime Field Result in New Feature Class
12:02:00 AM

getDateTime Variable - CalcDateTime field result in the New Feature Class concatenated with the Date field from the CSV File

6/29/2016 12:02:00 AM

FULL CODE BELOW

import arcpy
import datetime

def getdate(Hour, Minute):
return datetime.datetime.strptime(str(Hour).zfill(2) + ' ' + str(Minute).zfill(2), '%H %M')

fc = r'C:\Users\\Collar\BearLocationImports.gdb\BearCollar'

cursor = arcpy.da.InsertCursor (fc,["CollarSeri", "Year", "Julianday", "Hour", "Minute", "Activity", "Temperatur", "Latitude", "Longitude", "HDOP", "NumSats", "FixTime", "Date", "_2D_3D", "BearID", "CalcDate", "CalcDate3", "SHAPE@XY"])

for ln in open (r"C:\Users\tjv36463\Desktop\Bear Collar\rangedate_D032495_20160822124736_NH.txt", 'r').readlines():

#Each line in the csv is a string, so turn it into a list so you can reference each column
lineSplit = ln.split(",")

#Use index positions to get the right column from the csv
#Make sure the data is the correct type (i.e. X and Y need to be numbers, not strings)
CollarSeri = long(lineSplit[0])
Year = str(lineSplit[1])
Julianday = str(lineSplit[2])
Hour = int(lineSplit[3])
Minute = int(lineSplit[4])
Activity = int(lineSplit[5])
Temperature = int(lineSplit[6])
Latitude = float(lineSplit[7])
Longitude = float(lineSplit[8])
HDOP = str(lineSplit[9])
NumSats = int(lineSplit[10])
FixTime = int(lineSplit[11])
_2D_3D = int(lineSplit[12])

BearID = 0

Date = str(lineSplit[13]) # working with Date Time http://stackoverflow.com/questions/1521906/how-to-specify-date-and-time-in-python

getTime = getdate(Hour, Minute)
getTime2 = str(getTime)
getTime3 = getTime2[-8:]

getDateTime = (Date + getTime3)
print getDateTime

shapeVal = (Longitude, Latitude)

#Insert the values from csv into feature class
cursor.insertRow ([CollarSeri, Year, Julianday, Hour, Minute, Activity, Temperature, Latitude, Longitude, HDOP, NumSats, FixTime, Date, _2D_3D, BearID, getTime3, getDateTime, shapeVal])

count += 1

del cursor
print ("done")

Re: Calculate Date Field.

jaykapalczynski — Wed, 05 Oct 2016 01:40:01 GMT

Dude cant thank you enough for all your help…it is so gratefully appreciated.

Thanks

Jay

Jay Kapalczynski

GIS Coordinator - Virginia Department of Game & Inland Fisheries

(new address) 7870 Villa Park Drive Suite 400, Henrico VA 23228

Phone: 804.367.6796 | Fax: 804.367.2628

ü Please consider the environment before printing this email.