remove duplicate list elements

Question

I want to remove the duplicate elements in a list only when one element is repeated many times, like this:

li = ['Human','Human','Human'] => li = ['Human']

but not when there are two or more different elements:

li = ['Human','Monkey','Human', 'Human']

@S.Lott: I did that mistake too, but read the second line.. ^^ — poke
– poke, Commented Sep 29, 2010 at 22:20
@S. Lott. because he only wants duplicates removed if there is only one distinct value in the list. ordering might also be a concern. — aaronasterling
– aaronasterling, Commented Sep 29, 2010 at 22:20
This is homework. I saw it last semester. stackoverflow.com/questions/1549509/…, stackoverflow.com/questions/89178/…, etc. — S.Lott
– S.Lott, Commented Sep 29, 2010 at 22:23
Where did that answer disappear to? I thought that was correct? o.O — poke
– poke, Commented Sep 29, 2010 at 22:28

DarthJDG · Accepted Answer · 2011-06-27 09:35:36Z

4

You can do it easily with sets as below:

li = list(set(li))

DarthJDG

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answered Jun 27, 2011 at 8:53

user777847

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Comments

aaronasterling · Accepted Answer · 2010-09-29 22:16:50Z

3

def clean(lst):
    if lst.count(lst[0]) == len(lst):
        return [lst[0]]
    else:
        return lst

Does that do what you want?

if so, then you can do it in place as well

def clean_in_place(lst):
    if lst.count(lst[0]) == len(lst):
        lst[:] = [lst[0]]

answered Sep 29, 2010 at 22:05

aaronasterling

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That works great! btw was how do you clean duplicates if the successive elements are same, like ['a','a','a','b','a','a'] to ['a','b','a']

user1335578 · Accepted Answer · 2012-04-16 06:06:33Z

2

lst = ['Human','Human','Human'] => lst = ['Human']
lst = ['Human','Monkey','Human', 'Human'] => lst = ['Human','Monkey','Human', 'Human']

it was do what you want?

if lst.count(lst[0])==len(lst):
   lst=list(set(lst))
   print lst 
else:
   print lst

answered Apr 16, 2012 at 6:06

user1335578

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