ReplaceByBoolMask.py

import clr
clr.AddReference('ProtoGeometry')
from Autodesk.DesignScript.Geometry import *
#The inputs to this node will be stored as a list in the IN variables.
dataEnteringNode = IN

list = IN[0]
replace = IN[1]
bool_list = IN[2]

i = 0

for bool in bool_list:
	if bool : list[i] = replace
	i = i + 1

#Assign your output to the OUT variable.
OUT = list