How to check all elements of a list are same or different

[Chris Rebert]

> On Wed, Apr 15, 2009 at 5:49 PM, Chris Rebert <clp2 at rebertia.com> wrote:
>>
>> On Wed, Apr 15, 2009 at 2:36 PM, Gaurav Moghe <moghegau at msu.edu> wrote:
>> > Hi,
>> >
>> > I am an amateur python user I wanted to know how do I know whether all
>> > the
>> > contents of a list are all same or all different? Now, I could certainly
>> > write a loop with a counter. But is there a ready command for that?
>> > Checked
>> > a lot of docs and this mailing list, but didnt get anything worthwhile.
>> > Would be glad to know.
>>
>> All same:
>>
>> list_1 == list_2
>>
>> All different:
>>
>> all(x != y for x, y in zip(list_1, list_2))
>>
On Wed, Apr 15, 2009 at 2:55 PM, Gaurav Moghe <moghegau at msu.edu> wrote:
> Hi Chris,
>
> Thanks for the reply. But I am interested in analysing the contents of just
> one list. For example,
>
> list1=[1,2,3,4,5,6]
> So, the logical statement would probably be:
> if list1==(contains all same values), print "Same"    ---->False
> if list1==(contains all different values), print "Different"  ---->True
>
> I wanted to know here whether there is a command/function that can do
> exactly this.  I hope I am more clearer than my last try!

Ah, okay. Then you want:

def all_same(lst):
    return len(set(lst)) == 1

def all_different(lst):
    return len(set(lst)) == len(lst)

Note that these require all the elements of the list to be hashable.

Cheers,
Chris
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