Howw to prevent the duplication of any value in a column within a CSV file (python)

[Adam Davis]

On Tuesday, 26 April 2016 20:52:54 UTC+1, Ian  wrote:
> On Tue, Apr 26, 2016 at 1:05 PM, Joaquin Alzola
> <Joaquin.Alzola at lebara.com> wrote:
> > Just an example. Didn't use the csv but just hope that it helps.
> >
> > name=[]
> > name_exist="Dop"
> >
> > with open("dop.csv") as f:
> >         for line in f:
> >                 line_split=line.split(',')
> >                 name.append(line_strip[0])
> >         if name_exist in name:
> >                 print "found name " + name_exist + " Can not append"
> >         else:
> >                 file = open("dop.csv",'a')
> >                 print "No name found"
> >                 file.write(name_exist)
> > file.close()
> 
> Except that as noted elsewhere in the thread a set would be a better
> choice than a list, since checking membership is much faster on a set.

Thanks for your help Ian. I'm a beginner right now, could you instruct me as to how I would create a set?