topic Re: Search Cursor against date field and using date with python in Python Questions

Search Cursor against date field and using date with python

AliciaMein — Fri, 16 May 2014 19:23:02 GMT

Good Afternoon ArcPy Wizards!

I would love some input on my code.
I am trying to capture the earliest positive in a grid and then count the negative sample that were required before the positive.

The Code:

 for grid in grids:         dates = []         arcpy.SelectLayerByLocation_management("cwdpts4Anlys", "WITHIN", grid.shape, "NEW_SELECTION")         positives = arcpy.SearchCursor("cwdpts4Anlys",' "ELISALYMPHNODE" = \'Positive\' ' , "", "SAMPLE_ DATE" ')          for positive in positives:             dates.append(row[0])                  earliest = min(dates)         arcpy.SelectLayerByLocation_management("cwdpts4Anlys", "WITHIN", grid.shape, "NEW_SELECTION")         arcpy.SelectLayerByAttribute_management("cwdpts4Anlys", "SUBSET_SELECTION", ' "ELISALYMPHNODE" = \'Negative\' ')         arcpy.SelectLayerByAttribute_management("cwdpts4Anlys","SUBSET_SELECTION",'"SAMPLE_DATE" <= date earliest ' )         negatives = int(arcpy.GetCount_management("cwdpts4Anlys").getOutput(0))         grid.setValue('NegPrior2Pos', negatives)         grids.updateRow(grid)

I get a syntax error at

positives = arcpy.SearchCursor("cwdpts4Anlys",' "ELISALYMPHNODE" = \'Positive\' ' , "", "SAMPLE_ DATE" ')

Ive tried adding the keyword date before "SAMPLE_DATE" and many other ways.

Thanks!
Alicia

Re: Search Cursor against date field and using date with python

JamesCrandall — Fri, 16 May 2014 19:28:04 GMT

 positives = arcpy.SearchCursor("cwdpts4Anlys",' "ELISALYMPHNODE" = \'Positive\' ' , "", "SAMPLE_ DATE" '

Just a quick note: you have it as "SAMPLE_ DATE", not "SAMPLE_DATE". It could just be a copy/paste into the forum post editor, but you may want to take a quick look at your source code to verify this isn't the problem.

Re: Search Cursor against date field and using date with python

IanMurray — Fri, 10 Dec 2021 21:02:59 GMT

positives = arcpy.SearchCursor("cwdpts4Anlys",' "ELISALYMPHNODE" = \'Positive\' ' , "", "SAMPLE_ DATE" ')

I think you have an extra single quote at the end. You single quote for the expression ends at the end of the 2nd parameter, then I see no single quote for the one on the end to go with. SHould be like this I believe.


positives = arcpy.SearchCursor("cwdpts4Anlys",' "ELISALYMPHNODE" = \'Positive\' ' , "", "SAMPLE_ DATE" )

And yes, syntax errors are the devil.

Re: Search Cursor against date field and using date with python

AliciaMein — Fri, 10 Dec 2021 21:03:01 GMT

positives = arcpy.SearchCursor("cwdpts4Anlys",' "ELISALYMPHNODE" = \'Positive\' ' , "", "SAMPLE_ DATE" '
Just a quick note: you have it as "SAMPLE_ DATE", not "SAMPLE_DATE". It could just be a copy/paste into the forum post editor, but you may want to take a quick look at your source code to verify this isn't the problem.

I think your right, but I am also curious about how the date format is maintained.

When I set up the "dates" list, what is the format of the list?

Thanks,
Alicia

Re: Search Cursor against date field and using date with python

AliciaMein — Fri, 10 Dec 2021 21:03:04 GMT

positives = arcpy.SearchCursor("cwdpts4Anlys",' "ELISALYMPHNODE" = \'Positive\' ' , "", "SAMPLE_ DATE" ')
I think you have an extra single quote at the end. You single quote for the expression ends at the end of the 2nd parameter, then I see no single quote for the one on the end to go with. SHould be like this I believe.
positives = arcpy.SearchCursor("cwdpts4Anlys",' "ELISALYMPHNODE" = \'Positive\' ' , "", "SAMPLE_ DATE" )
And yes, syntax errors are the devil.

I missed that! Thanks