Extracting data using arcpy.da.SearchCursor?

Question

I have a shapefile of point features showing fire locations in a given year. One of the fields is named "YYYYMMDD" and indicates the corresponding date that that fire happened. In Python, I am trying to use the arcpy.da.SearchCursor function to append each date into a list and find the most recent fire by date.

My code looks like this:

listname = []
cursor = arcpy.da.SearchCursor(fires, "YYYYMMDD")
for row in cursor:
 listname.append(row)
print 'the first fire date is ',min(listname),'.'
print 'the last fire date is ',max(listname),'.'

What prints for min and max listname is: (20010515.0,) and (20011002.0,) But what I would like to get as an output is: 20010514 and 20011002

How do can I get that as my output?

I tried indexing what I got to exclude what I don't need but that doesn't work.

Answer 1

You need to grab the first element of each row and convert to int.

listname = []
cursor = arcpy.da.SearchCursor(fires, "YYYYMMDD")
for row in cursor:
 listname.append(int(row[0]))
print 'the first fire date is {0}.'.format(min(listname))
print 'the last fire date is {0}.'.format(max(listname))

• GeoSharp: You may also want to utilize a sql_clause in your search cursor something like sqlClause = (None, ‘ORDER BY ‘ + "YYYYMMDD" + ‘ DESC’) and then add that to your Search Cursor like this: cursor = arcpy.da.SearchCursor(fires, "YYYYMMDD", sql_clause = sqlClause). That way your field will already be sorted.

Answer 2

try it like this:

In your cursor loop - change to:

listname.append(row[0])

and for your printing - change to:

print "The first fire date is {0}".format(min(listname))
print "The last fire date is {0}".format(max(listname))

Answer 3

you should note that, in your case, row is a list (even if there is only one field). so listname becomes a list of lists. you need to take the value out of your list.

listname = []
cursor = arcpy.da.SearchCursor(fires, "YYYYMMDD")
for row in cursor:
 listname.append(row[0])

then you can format it as you want, e.g. :

print "the first date is " + str(min(listname))