I am using ArcMap.

In the labels I want to alter the text that is displayed, I do not want to change the data in the attribute table.

In the label expression I add the following after checking the advanced checkbox:

def FindLabel ([sur_notes]):
  return [sur_notes].replace('a string', 'another string')‍‍

The idea is to replace part of a string in the label from the sur_notes text field, however the above throws a syntax error.

I have checked the parser, it is set to python. The string is stored as text.

  • 1
    Did you check the Advanced checkbox?
    – Berend
    Jan 6, 2022 at 10:42
  • yes, this is in the advanced area Jan 6, 2022 at 10:42
  • I suspect you have null data in your sur_notes field. So replace won't work. You need to put a check for null in your code and deal with that.
    – Hornbydd
    Jan 6, 2022 at 14:37

1 Answer 1


When I copied your expression to ArcMap, I got the same error message, which in this case seemed to be caused by two invisible trailing characters after the closing ).

I solved it by placing the cursor there, and pressing backspace until ) was gone. Then I added ) again.

For those who are interested, the characters appeared to be Zero-width joiners. Pasting the snippet from the question in Notepad++, and then opening the file in a hex editor will reveal: E2 80 8D (which is the character's code point, U+200D) twice.

  • Thanks, I have typed out the whole text to avoid such an issue, I still get the error stating Error 0 on line 0 saying Attribute Error: NoneType object has no attribute replace Therefore the issue seems to be the parser not recognising the replace() function. Jan 6, 2022 at 12:55
  • @SpatialDigger I tried that too, and it worked. Other than the trailing characters, your code should work just fine.
    – Berend
    Jan 6, 2022 at 14:04

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