Newbie: Why wouldn't this simple code work?

Question

Purpose:
I have 1 field in a large table with numbers in mm, want to show in m. Want to use python to multiply by 1000. Want to use the Python Field Calculator for this.

Code:def func( height ):  return (height*1000)

HEIGHT_MM= func(!HEIGHT_MM)

Result:
the code succeeds (no syntax errors), but nothing happens to the numbers in my field!

DarrenWiens2 · Accepted Answer

You need another exclamation mark around the field name. I'm a little bit surprised that it ran at all. It may be interpretting the one exclamation as "if HEIGHT_MM does not exist".HEIGHT_MM= func(!HEIGHT_MM!)