topic Re: Help with dynamic label python code in Python Questions

Help with dynamic label python code

SeanEdwards — Thu, 14 Jul 2016 20:36:17 GMT

Hello friend. I am pretty basic with Python and have a question about writing out a label.

I have an attribute table with multiple fields with floating point acreages in the fields. Not all of the fields necessarily have to contain a value; most of them are <Null>.

I am trying to build a label expression for a data driven map book that looks at the fields, and if it it has a value, add it to the label with leading text, then look at the next field. So far, I have using the IF statement and once the statement is true, it stops and does not search for the other true values.

Is there any If-and statement that I can use?

My code:

Function FindLabel ( [BLM] , [BR] , [Private] , [SITLA] )

if ( ( [BLM] ) > 0) then

FindLabel = "BLM: " + [BLM] + " acres"

elseif ( ( [BR] ) > 0) then

FindLabel = "BR: " + [BR] + " acres"

elseif ( ( [Private] ) > 0) then

FindLabel = "Private: " + [Private] + " acres"

elseif ( ( [SITLA] ) > 0) then

FindLabel = "SITLA: " + [SITLA] + " acres"

end if

End Function

Assuming that there were acreages in each of the fields except [BR], I would want the label to read

BLM: 44.59 acres

Private: 89.01 acres

SITLA: 1.89 acres

Thanks for any help!

Re: Help with dynamic label python code

RandyBurton — Fri, 10 Dec 2021 23:28:59 GMT

If you are wanting to print the possible combinations, you wouldn't use an elseif. Try something like this (but adapted for FindLabel):

BLM = 5.5
BR = None
PVT =  6.5
SITLA = 7.5
label_str = ""

if BLM : label_str = "BLM: " + str(BLM) + " acres\n"
if BR : label_str = label_str + "BR: " + str(BR) + " acres\n"
if PVT : label_str = label_str + "PVT: " + str(PVT) + " acres\n"
if SITLA : label_str = label_str + "SITLA: " + str(SITLA) + " acres\n"

find_label = label_str
print find_label

Re: Help with dynamic label python code

BlakeTerhune — Thu, 14 Jul 2016 22:29:09 GMT

If you use str.format() it will automatically make the non-string values text instead of having to do it manually. You can also use += to add to an existing value.

label_str += "BR: {} acres\n".format(BR)

Re: Help with dynamic label python code

RandyBurton — Fri, 10 Dec 2021 23:29:02 GMT

Here's a rewrite of your FindLabel function. It uses Blake's suggestions; there are a number of ways to do the same thing in Python.

def FindLabel ([BLM], [BR], [Private], [SITLA]):
    label_str = ""
    if [BLM] : label_str += "BLM: {} acres\n".format([BLM])
    if [BR] : label_str += "BR: {} acres\n".format([BR])
    if [Private] : label_str += "Private: {} acres\n".format([Private])
    if [SITLA] : label_str += "SITLA: {} acres\n".format([SITLA])
    return label_str.strip()