FME 2020 Python feature.removeAttribute(attr)

I have a pythoncaller, that runs the below python, this works OK in FME 2018, but fails in 2020.

ERROR |Python Exception <SyntaxError>: invalid syntax (<string>, line 11)

FATAL |Factory proxy not initialized

I have the python interpreter set to 3.6+

So the script works in 2020 if I tag out the last line, so has something changed with the feature.removeAttribute function ?

import fmeobjects

def removeNulls(feature):

attrsin = feature.getAttribute('SRC_ATTRS')

attrs = attrsin.split(',')

for attr in attrs:

val = feature.getAttribute(attr)

if val == 'VCP' :

feature.setAttribute('attname',attr)

if val <> 'VCP' :

feature.removeAttribute(attr)