Question

Suppose I have a variable S with the string "1:3" (or for that matter, "1", or "1:" or ":3") and I want to use that as a slice specifier on list L. You cannot simply do L[S] since the required args for a slice are "int:int".

Now, I current have some ugly code that parses S into its two constituent ints and deals with all the edge cases (4 of them) to come up with the correct slice access but this is just plain ugly and unpythonic.

How do I elegantly take string S and use it as my slice specifier?

Answer 1

Here’s another solution

eval("L[%s]" % S) 

warning – It’s not safe if S is coming from an external(unreliable) source.