Kent Johnson wrote: >Olli Rajala wrote: > > >>Hi again, >> >>I have a '2D array', I mean a list inside a list ([[][],[][],...]) and >>would need to check if the value exists in it. Of course I could do a >>for loop, but that just seem to be a little overkill, so is there any >>other way to do it? I have to check the first cell of every insider >>list. >> >> > >With Python 2.4: > >>> l= [ [1], [2,3], [4,5], [6]] > >>> 2 in (i[0] for i in l) >True > >>> 3 in (i[0] for i in l) >False > >with Python 2.3 use [i[0] for i in l] instead which is a little less efficient. > The second case you show should be true because I believe that's what he asked for. Here is I believe the correct way to do this.
>>> l= [ [1], [2,3], [4,5], [6]] >>> def isin(test,alist): ... return bool([x for x in alist if test in x]) ... >>> isin(2,l) True >>> isin(3,l) True >>> isin(10,l) False >>> def isin2(test,alist): ... for x in alist: ... if test in x: ... return True ... return False >>> isin2(2,l) True >>> isin2(10,l) False >>> __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
