generating unique variable name via loops

[Fatih Güven]

Hi,

I want to generate a unique variable name for list using python.

list1=...
list2=...
.
.
.
listx=... where x is a number.

You can remember it from saving a file in a directory. If you have already created a "new file", save dialog sugget that <<"new file " is already exist, do you want to save it as "new file (1)"?>> so I want to apply it for list names. 

Do you any idea about this.