Field calculation using Python Parser

Question

I have a table as like below:

enter image description here

I want to generate python script to calculate the value Low, Medium and High into a single layer.

I tried using this script:

Parser:
Python
Expression:
Reclass( Flood_Severity )
Code Block:
def Reclass ( Flood_Severity ):
 if ( FAT = 1 and FV = 1 and FD < 3):
 return "Low"
 elif ( FAT = 1 and FV = 1 and FD >= 3):
 return "Medium"
 elif ( FAT = 1 and FV = 2 and FD = 1):
 return "Low"
 elif ( FAT = 1 and FV = 2 and FD > 1 and FD < 4):
 return "Medium"
 elif ( FAT = 1 and FV = 2 and FD=4):
 return "High"

But it failed. May I know how to fix the script?

• Bera: Failed how? Do you get errors? Your table cant look like that in ArcMap, can you add a screenshot showing the attribute table
• Hornbydd: I agree with @BERA you need to edit your question and include an image of your data as it is in ArcMap.
• FelixIP: Table shown cannot be analyzed. It looks like result of normal flat database table pivoted in Excel or similar.

Answer 1

You are going to get errors for using = as a comparison operator , it should be two ==.

See: Python Operators

And you need to include all the fields you use in the function, when declaring and calling it:

def Reclass ( FAT, FV, FD ):
 ...

And when you call it:

Reclass( !FAT!, !FV!, !FD! )