In ArcGIS 10.5, I am building a model that should convert a field of coded values to another code. This seems like it should be a simple if/then statement but I am not getting it. To simplify the process, I populated the target field with the source field's values and then intend on using python to transpose the values. It should be considered a string, but the values are numerical. The field I am trying to edit is "TP_Condi"

In the "Calculate Field" code block:

def reclass:  
if TP_Condi = 3:    
     return 1    
elif TP_Condi = 2:     
     return 8  
elif TP_Condi = 1:    
     return 3  
     return "error" 

This is the code I was seeking:

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  • 1
    You need double == when you evaluate a condition, for example if TP_Condi == 3. Take a look at the examples here: desktop.arcgis.com/en/arcmap/10.3/manage-data/tables/…
    – BERA
    Feb 22, 2018 at 14:27
  • 1
    You also need to indent everything under reclass by 4 spaces
    – s6hebern
    Feb 22, 2018 at 14:31
  • I'd suggest spending a few hours on a quick online Python primer, your code has at least 4 different problems that I can see. The difference between = and == in particular is covered very early in just about every Python course I've seen.
    – Dan C
    Feb 22, 2018 at 14:51
  • I've spent days...it is not coming very easy to me
    – cpbride
    Feb 22, 2018 at 14:54
  • What is the field type of TP_Condi?
    – BERA
    Feb 22, 2018 at 15:03

1 Answer 1


As per comments above, you need to use double equals signs and indent the lines within your function definition.

def reclass(TP_Condi):  
  if TP_Condi == 3:    
     return 1    
  elif TP_Condi == 2:     
     return 8  
  elif TP_Condi == 1:    
     return 3  
     return 0
  • 2
    @cpbride please accept this answer if it solved your issue
    – underdark
    Feb 22, 2018 at 19:10

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