topic Re: Combining a date and time field in Python Questions

Combining a date and time field

Anonymous User — Mon, 09 Dec 2019 10:04:20 GMT

I have a point shapefile with a date field, called "Date" which is a Date type field. And I have a time field, called "Time" which is in a String format.

How can I combine these to allow me to enable the use of time for the shapefile? The only solutions I have found are if these field are both in string format, but I am not sure how to convert the date field to string, using [Date].AsString didn't seem to work

If anyone can help that would be amazing, if possible please be very specific in your response as I am quite a beginner at this sort of stuff.

Thanks

Re: Combining a date and time field

JoshuaBixby — Mon, 09 Dec 2019 16:48:32 GMT

Can you elaborate on:

using [Date].AsString didn't seem to work

Did you get an error? If so, what? Or, were the result just unexpected, and what did you expect?

Re: Combining a date and time field

Anonymous User — Mon, 09 Dec 2019 17:13:28 GMT

So I had found a possible solution but both fields had to be in String format, so was attempting to convert the Date field to a String field. That's it really, error as follows

Re: Combining a date and time field

JoshuaBixby — Tue, 10 Dec 2019 22:49:42 GMT

Where did you get "AsString", here How To: Convert a number field to a string field ? AsString is not a valid VB or Python function/method.

I suggest you use Python, but if you are set on using VB, then take a look at VBScript convert date to string - Stack Overflow

Re: Combining a date and time field

JoeBorgione — Tue, 10 Dec 2019 23:02:33 GMT

I wonder if you could use strftime() to convert your date field to a string, and then merge with your string time field, and then use strptime() to convert that whole mess back to a real live date/time value.

Are you really using shapefiles? I thought the dbf of a shapefile didn't support a date field...

Re: Combining a date and time field

JoshuaBixby — Wed, 11 Dec 2019 00:24:21 GMT

Joe, the current dBASE file format supports a timestamp field: dBASE .DBF File Structure. That said, timestamp is new in version 7 (Beginners’ Corner (Part 2) - The dBASE Tables )

* Timestamp

New since Visual dBASE 7, Timestamp fields have a fixed width of eight bytes and are used to store the date and time of a precise moment. Note: The time precision extends to the second.

Esri's shapefile is based on dBASE III, which does not include a timestamp field, but a date field is supported. So, you can store dates but not times.

Re: Combining a date and time field

JoeBorgione — Wed, 11 Dec 2019 13:33:02 GMT

Just goes to show how often I use shape files. Years a go I responded to a post on the old forum that a friend had made. I don't remember the exact subject, but it involed shape files. With tongue firmly planted in cheek, I posted a comment to him saying 'You know Bob, shape files are now illegal in 14 states....' Holy cow, the frantic comments that followed...

Re: Combining a date and time field

Anonymous User — Thu, 12 Dec 2019 12:02:22 GMT

I'll give it a try. Thanks. I've created a shapefile from a csv I was given. Apologies for my lack of knowledge, I only dip in and out of GIS work, what would you otherwise use instead of a shapefile?

Re: Combining a date and time field

JoeBorgione — Thu, 12 Dec 2019 12:24:49 GMT

I use some flavor of geodatabase feature class. Occasionally I'll export a feature class to a shape file, zip all the components up and email the zip file to a colleague. But in terms of day to day data analysis, feature classes only.

Re: Combining a date and time field

Anonymous User — Thu, 12 Dec 2019 12:28:36 GMT

Thanks, I always thought a geodatabase was essentially a folder, and shapefiles resided within! I shall try it out

Re: Combining a date and time field

JoeBorgione — Thu, 12 Dec 2019 13:09:03 GMT

Many times the term shapefile is used generically, if not incorrectly; hence my question as to whether or not you are truly using shapefiles. Windows explorer 'sees' a file geodatase as a folder, but it is truly a database.

What is a geodatabase?—ArcGIS Help | ArcGIS Desktop

What is a shapefile?—Help | ArcGIS for Desktop

What is ArcGIS? | ArcGIS for Developers

Re: Combining a date and time field

Anonymous User — Thu, 12 Dec 2019 16:09:28 GMT

By way of a solution to my original question, here is what I did for anyone else who comes across this:

I originally had a csv file, I used Access to ensure both the Date and Time fields were in string format, and exported as a text file. I then imported the text file into Arc, and created a point feature class from the file.

I then created a new field (called DateTime), this new field type was 'Date'.

Then, using the field calculator I combined the Date and Time fields in this new field using the following (Python parse):

datetime.datetime.strptime("{} {}".format(!Date!, !Time!), "%d/%m/%Y %H:%M:%S")

Re: Combining a date and time field

JoeBorgione — Thu, 12 Dec 2019 17:07:06 GMT

The csv file represents what type of geometry? I suspect points. Or is it just a table?

At any rate, more suggested reading:

Create points from a table—ArcGIS Pro | Documentation

Table To Table—Conversion toolbox | ArcGIS Desktop

You might be able to skip the Access step....