The Jacl scripting language, does not have null values. Whereas the Jython scripting language, does have a None value which is similar to Null in the Java™ programming language. Hence, Jacl scripts which check for an empty string might need to have the preliminary converted Jython scripts manually modified to also check for a possible None value. This depends on whether or not the variable can have a None value.
JACL: if {x==""} ==> JYTHON: if (x==None or x=="") #might need manually check for None values