Keeping Empty ShapeFiles?

Question

Hello All, I am trying to create a tool in python that can potentially find areas of wind turbines by county. I have the correct process down, but in some counties there are parameters that don't exist. So for example I take into account airports, hydrology, slope, roads, urban areas, and more. But what if an area does not have that parameter ie. no military zones in some counties. But I have a code that requires the military area. Is there a way to use the tool so that it can ignore certain parameters when there is no data? Below is the piece of code that is giving me issues. I would still like to use this code, but I need it to work when there is no data in some of the shape files. I feel there is a way to do this without having to write a ton of if-then blocks. Thanks in advance! arcpy.analysis.Union([Airports, Native, Parks, BufRail, Urban, BufRoads, Forests, Military, BufStreams, BufWaterBodies], Workings+"Avoid.shp", "ALL", None, "GAPS")‍ -Aaron

AaronChristiansen · Answer

Thank you so much!

This will definitely help me!

Best,

Aaron

XanderBakker · Answer

If each has it's own variable, you can validate to see if it is empty and exclude it from the list. Look at the snippet below: Airports = r'blah 1' Native = r'blah 2' Parks = None # not sure if it will be an empty string or null BufRail = r'blah 4' Urban = r'blah 5' BufRoads = '' # not sure if it will be an empty string or null Forests = r'blah 6' Military = r'blah 7' BufStreams = None # not sure if it will be an empty string or null BufWaterBodies = r'blah 8' lst = [Airports, Native, Parks, BufRail, Urban, BufRoads, Forests, Military, BufStreams, BufWaterBodies] new_lst1 = [a for a in lst if a != ''] new_lst2 = [a for a in lst if a != None] new_lst3 = [a for a in lst if a != None and a != ''] print lst print new_lst1 print new_lst2 print new_lst3 ‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍ This will yield: ['blah 1', 'blah 2', None, 'blah 4', 'blah 5', '', 'blah 6', 'blah 7', None, 'blah 8'] ['blah 1', 'blah 2', None, 'blah 4', 'blah 5', 'blah 6', 'blah 7', None, 'blah 8'] ['blah 1', 'blah 2', 'blah 4', 'blah 5', '', 'blah 6', 'blah 7', 'blah 8'] ['blah 1', 'blah 2', 'blah 4', 'blah 5', 'blah 6', 'blah 7', 'blah 8']‍‍‍‍ Use the new list in the Union: arcpy.analysis.Union(new_lst3, Workings+"Avoid.shp", "ALL", None, "GAPS")‍ You will probably have to check to see if the list has at least 2 items to avoid problems.

AaronChristiansen · Answer

So each input has been specified in precursor code using a gui and each layer is a separate parameter.