topic Date field to number field (yyyy/mm/dd) in Python Questions

Date field to number field (yyyy/mm/dd)

ChrisHanes — Wed, 15 Aug 2012 22:43:23 GMT

I am trying to use calculate field to populate a number field with a date. In ArcMap/Catalog, the field calculation would be like this:

field1 = "format([field2], "yyyymmdd")

Where field1 is a number field and field2 is a date field

I cannot get this to work in Python though. I tried several different ways and it throws errors when it gets there:

gp.CalculateField_management(input_layer, "field1", "format([field2], "yyyymmdd")", "VB", "")

Expression1 = """format([field2],"yyyymmdd")"""
gp.CalculateField_management(input_layer, "field1", Expression1, "VB", "")

gp.CalculateField_management(input_layer, "field1", "format([field2], \"yyyymmdd\")", "VB", "")

None of these worked. I made a model (ran it to test) and outputted to a script. It gave me the same syntax as the last one (with the back slashes). I ran that in my script and it still failed. I then tried making a feature class from the layer first, thinking it might not want a layer input and that didn't help. I tried one last change (making it "PYTHON_9.3" instead of "VB" in the line of code and that crashed it when it ran.

Can anybody help me pass the string value with imbedded quotes in there correctly?

Re: Date field to number field (yyyy/mm/dd)

SolomonPulapkura — Thu, 16 Aug 2012 15:32:56 GMT

format to pass string with quotes is

"\"yyyymmdd\""

hope this helps.

Re: Date field to number field (yyyy/mm/dd)

ChrisHanes — Thu, 16 Aug 2012 15:42:38 GMT

This tells me "unexpected character after line continuation character":

gp.CalculateField_management(stat_3e, "tognum", "format( [PatIssDate], "\"yyyymmdd\""")", "VB", "")

stat_3e is my input layer, "tognum" is field name to calculate, PatIssDate is field I am calculating from.

Can you post the entire line of code? I'm not sure I inserted your code right. It seems to have issue with the first slash in your portion (I made red) because PyScripter changed the color of it.

Re: Date field to number field (yyyy/mm/dd)

ChrisHanes — Thu, 16 Aug 2012 16:57:19 GMT

I actually misspoke about the source field. It is actually text, not a date field. But I still have the same issue with using the format command in Python.

A developer I spoke to suggested not using the command at all saying it probably wouldn't work in 10.1 given the lack of support for VB.

He suggested using a code block to calculate it manually (parsing by the slash).

Re: Date field to number field (yyyy/mm/dd)

RobertMartin2 — Thu, 16 Aug 2012 17:26:09 GMT

It looks like VB is supported - in fact it's the default - in 10.1.

http://resources.arcgis.com/en/help/main/10.1/index.html#/Calculate_Field/00170000004m000000/

Good luck with this!