topic Re: Trying to calculate values from two different tables using SearchCursor in Python Questions

Trying to calculate values from two different tables using SearchCursor

DavidHarlan — Wed, 09 Nov 2011 13:11:25 GMT

It seems like this should be easy but my script is choking on something. I have two dbf tables that each have a field "SUM_LENGTH". I want to divide the value of one field by the other. Each table only has one row so I thought next() would be appropriate to access the row and GetValue would return the value. I am doing something wrong though. Any ideas?

strcur = gp.SearchCursor(streamtable,"", "","SUM_LENGTH","")
Artcur = gp.SearchCursor(Arttable, "", "", "SUM_LENGTH", "")
strrow = strcur.next()
artrow = Artcur.next()
strlen = strrow.GetValue("SUM_LENGTH")
artlen = artrow.GetValue("SUM_LENGTH")

index = artlen / strlen
print index
del Artcur
del strcur

#thanks

Re: Trying to calculate values from two different tables using SearchCursor

ChrisSnyder — Wed, 09 Nov 2011 14:20:14 GMT

getvalue() is for retreiving values when the field name is stored as a variable. In your case, you don't need it, since you already know the field name.

Since there is only a single record in the tables, how about:

strlen = gp.SearchCursor(streamtable,"", "","","").next().SUM_LENGTH
artlen = gp.SearchCursor(Arttable,"", "","","").next().SUM_LENGTH
index = artlen / float(strlen)
print index
del strlen, artlen

Re: Trying to calculate values from two different tables using SearchCursor

DavidHarlan — Wed, 09 Nov 2011 14:53:45 GMT

Thanks a bunch Chris. I'm pretty new at this and as usual I'm making it more complicated that it needs to be. Python is a harsh mistress, yes?

Re: Trying to calculate values from two different tables using SearchCursor

ChrisSnyder — Wed, 09 Nov 2011 16:10:45 GMT

Harsh at first perhaps.... Once you understand her though, she is a real gem 😉