Geographic Information Systems Stack Exchange is a question and answer site for cartographers, geographers and GIS professionals. It only takes a minute to sign up.
Sign up to join this community
I have been trying to rework attributes in a polygon shapefile and think I have figured out how to ask in a sensible manor.
I need to fill column Field2 with a 1 IF the value in column Field1 is equal to a certain value.
For instance I want a 1 in my field "Greenspace" if my field "leisure" has the value 'park' or 'golf_course' in the column.
On field Greenspace open Field Calculator, set to Python Parser, and turn on Code Block.
In the Code Block:
def rework(leisure, greenspace):
if leisure == 'park' or leisure == 'golf_course':
return 1
else:
return greenspace
And in the expression:
rework(!leisure!, !Greenspace!)
The return greenspace here leaves any existing values in Greenspace. If this isn't here the other values in the column will be set to Null
You can also put it all on a single line (without using the Code Block) which is nice and tidy if this is the only possible combination, but if you have other values (which you want to return as 2 or 3 etc.) it will be easier to use the code block above.
1 if !leisure! == "golf_course" or !leisure! == "park" else !Greenspace!
In response to your comments, you can also try:
def rework(leisure, greenspace):
if leisure in ['pitch', 'golf_course', 'sports_centre']:
return 'sports'
elif leisure in ['grass', 'park', 'playground']:
return 'park'
elif leisure in ['garden', 'trees']
return 'vegetation'
else:
return greenspace
if/elif/else
– Midavalo♦
Feb 13 '17 at 3:28
