topic Re: Fastest way to get number of rows in a da.SearchCursor in Python Questions

Fastest way to get number of rows in a da.SearchCursor

JohnDye — Thu, 23 Oct 2014 15:31:06 GMT

Anyone know of a quick way to count the number of records returned by a da.SearchCursor with a where_clause applied?

with arcpy.da.SearchCursor(MyLayer, "SHAPE@", SuperDuperAwesomeQuery) as rows:

# how do I figured out how many records are in rows without iterating through rows???

Re: Fastest way to get number of rows in a da.SearchCursor

JamesCrandall — Thu, 23 Oct 2014 15:53:47 GMT

arcgis desktop - Fastest way to count the number of features in a feature class? - Geographic Information Systems Stack …

Re: Fastest way to get number of rows in a da.SearchCursor

JamesCrandall — Thu, 23 Oct 2014 16:05:04 GMT

Alternative method (I don't know it this is faster):

sql = "ObjectId=1"
_dfsource = r'H:\Documents\ArcGIS\Default.gdb\L8_Parcel'
_numparr = arcpy.da.FeatureClassToNumPyArray(_dfsource, ["ObjectId"], sql)
rowcount = len(_numparr)
print rowcount

Re: Fastest way to get number of rows in a da.SearchCursor

JohnDye — Thu, 23 Oct 2014 16:52:00 GMT

Thanks James,

I was trying to avoid making a query table but it seems that's the the quickest approach that doesn't require iterating. However using the MakeQueryTable tool did require spinning up the geoprocessor which took some time so in the end I actually found it was still faster to just iterate and count the rows.

with arcpy.da.SearchCursor(FeatureLayer, "SHAPE@", SuperDuperAwesomeQuery) as rows:

rowCount = 0

for row in rows:

rowCount = rowCount + 1

print rowCount

del rows

Re: Fastest way to get number of rows in a da.SearchCursor

ChrisPedrezuela — Thu, 23 Oct 2014 17:33:21 GMT

row count = len(list(i for i in arcpy.da.SearchCursor(fc, fields, query)))

Re: Fastest way to get number of rows in a da.SearchCursor

JohnDye — Thu, 23 Oct 2014 17:43:22 GMT

Niiice. So obvious once I saw it. Sorry, I already gave the answer to James.