trying to match a string

[Scott David Daniels]

arnimavidyarthy at gmail.com wrote:
> I am taking a string as an input from the user and it should only
> contain the chars:L , M or R
How about skipping re's and doing something like:
    set(input_string) <= set('LMR')
If you want to disallow the empty string:
    set([]) < set(input_string) <= set('LMR')

--Scott David Daniels
Scott.Daniels at Acm.Org