How to append only the unique item on the list?

Question

I am hoping to find way to append only the unique item numlookup and wholetoken. Is there a good way to do this?

numlookup = defaultdict(list) 
wholetoken = defaultdict(list)

#mydata is file containing mutation description
mydata = open('/mutation_summary.txt')
for line in csv.reader(mydata, delimiter='\t'):
    code = re.match('[a-z](\d+)[a-z]', line[-1], re.I)
    if code: 
        numlookup[line[-2]].append(code.group(1))
        wholetoken[line[-2]].append(code.group(0))

When i try to use set i got this as error when i call lookup(id) and wholelookup(id): TypeError: 'set' object is not callable

lookup =set()
wholelookup =set()

with open('mutation_summary.txt') as mydata:
    for line in csv.reader(mydata, delimiter='\t'):
        code = re.match('[a-z](\d+)[a-z]', line[-1], re.I)
        if code: 
            lookup.add(code.group(1))
            wholelookup.add(code.group(0))

You mean the dictionary value is a `list` and you have to make sure the element of the list is unique? — quantum, Jul 25 '12 at 18:48
@xiaomao yes... if i use list i m not sure how to call it again — Chad D, Jul 25 '12 at 18:49
@KarolyHorvath order doesn't matter can i pass parameter in to a set? because i need to pass wholetoken(id) and numlookup(id) — Chad D, Jul 25 '12 at 18:59
Possibly useful: http://stackoverflow.com/questions/1653970/does-python-have-an-ordered-set — Daenyth, Jul 25 '12 at 19:05
that should work, you probably have a variable called `set` which masks the builtin set... — Karoly Horvath, Jul 25 '12 at 19:12
`x = set()` works for me. Did you assign something to set? http://stackoverflow.com/questions/6593979/how-to-convert-a-set-to-a-list-in-python — Lenna, Jul 25 '12 at 19:12
@Lenna the code works great until when i call the lookup(id) later on the program( the id is in line[-2] on that file so maybe that is the problem) — Chad D, Jul 25 '12 at 19:16
@ChadD: read what inspectorG4dget says: you can't index a set. — Lenna, Jul 25 '12 at 19:19

score 0 · Accepted Answer · answered Jul 25 '12 at 18:48

0

Why not turn it into a defaultdict of sets? It only keeps the uniques.

If that is not an option, then you could try:

if code:
    if code.group(1) not in numlookup[line[-2]]:
        numlookup[line[-2]].append(code.group(1))
    if code.group(0) not in wholetoken[line[-2]]:
        wholetoken[line[-2]].append(code.group(0))

answered Jul 25 '12 at 18:48

inspectorG4dget

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I am not sure how to call set on a other part of my code.. but with list i know how to call it.. like list[ids] would calling set with particular ids? – Chad D Jul 25 '12 at 18:52
That would work. You could also iterate over a `set`, though you can't index into it – inspectorG4dget Jul 25 '12 at 18:54
i don't really get that ... would it work if i put the pass something in for example whole token(id)? – Chad D Jul 25 '12 at 18:57
1

If you have a set containing the numbers `1,2,3,4,5` and you tried to insert `5`, it will just ignore the insert. If you try to insert `6`, it will insert `6`. You can iterate over a set (`for num in mySet: print num`). You cannot index into a set (`print mySet[4]` is not allowed) – inspectorG4dget Jul 25 '12 at 19:00
Nononono! I meant use `defaultdict(set)` – inspectorG4dget Jul 25 '12 at 19:09

How to append only the unique item on the list?

1 Answers1