Hello all: Having the following Python script: if same_type(RR,[]): return "It is a list" if same_type(RR,'abcd'): return "it is a string" If I use on the parameter's list (sme scrren where the Python script is edited) the value: RR=[['04-03-2001','0900','MEX','PBA','0300','N'],['04-03-2001','1100','MTY','NLD','0300','N'],['04-03-2001','1600','NLD','MTY','0300','N']] and proceed to TEST the script with the test tab, I am asked for the value of RR (two fields), if I give nothing, then the message "It is a list" is printed, as expected. But, if the same thing, (except the initial RR=) is fed into the values field at the test page, then the result comes as a "string", which is NOT the intended effect. This is just a brief test to find out what is going on, the goal is to be able to feed into a Python script, a list of lists that the script will process and output another list of lists. We have been unable to obtain this as the scripts always ends getting a string instead of the wanted list (of lists). Can anyone be so kind to explain the behavior of this ? And, to provide some samples on how to make this work correctly ? By the way, we started with a perfectly working *.py program file , converting it into a script which behave on a similar way to the test just shown. Thanks in advance for your help. Edward. Piensa Tech.