string to list when the contents is a list

[Wes James]

I have been trying to create a list form a string.  The string will be
a list (this is the contents will look like a list).  i.e. "[]" or
"['a','b']"

The "[]" is simple since I can just check if value == "[]" then return []

But with "['a','b']" I have tried and get:

a="['a','b']"

b=a[1:-1].split(',')

returns

[ " 'a' "," 'b' " ]

when I want it to return ['a','b'].

How can I do this?

thx,

-wes