Rank features by an attribute within groups of another attribute

LJackson29 — Thu, 13 May 2021 18:53:13 GMT

Using the below code in ArcGIS Pro Calculate Field, I was able to rank my data overall by score (descending - so high score gets a rank of 1) after permanently sorting my layer, but I would also like to rank scores within groups of 1 or 2 other fields for example within Watershed and within Watershed and County. Is there a way to add this to the code in Calculate Field?

Rank=getNextRank(!Score!)

Code Block

rank = 0
lastValue = None

def getNextRank(value):
global rank
global lastValue
if value == lastValue:
return rank
else:
rank+=1
lastValue = value
return rank

For example

Score	Watershed	County	Overall Rank	Rank_win_Watershed	Rank_win_WatershedCounty
30	A	1	5	2	1
10	A	1	7	3	2
70	A	2	1	1	1
25	B	1	6	2	1
40	B	2	4	1	1
30	C	1	5	3	1
60	C	2	2	1	1
55	C	2	3	2	2

Many thanks!

Re: Rank features by an attribute within groups of another attribute

JoshuaBixby — Thu, 13 May 2021 23:02:30 GMT

It is much easier with multi-group ranking to use cursors rather than Field Calculator. Something like this in the interactive Python window should work:

lyr = # name of layer or path to feature class or table sql = "ORDER BY watershed, county, score desc" flds = ["watershed", "county", "Rank_win_WatershedCounty"] with arcpy.da.UpdateCursor(lyr, flds, sql_clause=(None,sql)) as cur: cnt = 1 row = next(cur) cur.updateRow(row[0:2] + [cnt]) row_prev = row for row in cur: if row[0:2]==row_prev[0:2]: cnt += 1 else: cnt = 1 cur.updateRow(row[0:2] + [cnt]) row_prev = row

topic Rank features by an attribute within groups of another attribute in ArcGIS Pro Questions

Rank features by an attribute within groups of another attribute

Re: Rank features by an attribute within groups of another attribute