[Tutor] Help regarding reg exp.

[Danny Yoo]

> On 05/10/16 10:03, rakesh sharma wrote:
>> Hi all
>>
>> I have a string of pattern ({A,BC},{(A,B),(B,C)(C,A)}.
>

On Wed, Oct 5, 2016 at 3:14 AM, Alan Gauld via Tutor <tutor at python.org> wrote:
> Until we understand the data better we can't be sure
> a regex is the best solution.


Yes, I agree with Alan: we need to know more about the problem.

You've given one example.  Do you have a few more examples to give?
Why is your input a string, and not a structured object?  Where does
this input come from?


Generalizing a solution from an example set of size one is trivially
easy.  It doesn't need regexes or anything: it just needs a simple
string comparison:

###########################################
def solution(input):
    if input == "({A,BC},{(A,B),(B,C)(C,A)}":
        return "{A,B,C}"
###########################################

You might think that I'm joking.  This is a "ha, ha, just serious"
sort of thing.  In fact, this is exactly the first implementation I
would write if I were writing in test-driven-development mode.  It
forces me to write good test cases that actually exercise the solution
and to make sure I don't cheat like this.