Returning shape.area in code block of ArcGIS Field Calculator with if statement?

Question

Using ArcGIS 10.1 for Desktop, I try to calculate a field using an 'if' statement in the field calculator. Here is my code :

"
#Expression
MyField_2 = def Reclass(!MyField_1!)
#Parser
Python 9.3
#Code Block
def Reclass(MyField1) :
 if MyField1 == -1 :
 return 0
 else :
 return !shape.area!
"

But I have an error returning !shape.area!. How can I fix that ?

• ustroetz: I think !shape.area! also needs to be an argument in your Reclass function. But can you please post the error?
• MerlinLelutin: I have a 00089 error "Python parsing error line 5"

Answer 1

Instead of using a code block, you should be able to just do...

0 if !MyField_1! == -1 else !shape.area!

Answer 2

shape_area has to be an argument in your Reclass function.

Your expression should look like this:

Reclass( !MyField_1!,!shape.area!)

And your script code like this:

def Reclass(MyField1,shape_area):
 if MyField1 == -1:
 return 0
 else:
 return (shape_area)

• MerlinLelutin: Great, this works !

Answer 3

You are receiving an error because shape isn't being referenced.

One way to solve it would be to pass two parameters to your reclass function, like @ustroetz mentioned. The following code does this:

#Expression
Reclass(!MyField_1!, !shape.area!)
#Code block
def Reclass(test_field, shape):
 if test_field == -1:
 return 0
 else:
 return shape
#Or alternatively,
def Reclass(test_field, shape):
 return 0 if test_field == -1 else shape