Are all items in list the same?

[Dan Sommers]

On 1/8/19 2:31 PM, Tobiah wrote:> On 1/8/19 9:20 AM, Alister wrote:
 >> On Tue, 08 Jan 2019 17:15:17 +0000, Alister wrote:
 >>
 >>> On Tue, 08 Jan 2019 16:48:58 +0200, Serhiy Storchaka wrote:
 >>>
 >>>> 08.01.19 11:07, Peter Otten пише:
 >>>>> Bob van der Poel wrote:
 >>>>>
 >>>>>> I need to see if all the items in my list are the same. I was using
 >>>>>> set()
 >>>>>> for this, but that doesn't work if items are themselves lists. So,
 >>>>>> assuming that a is a list of some things, the best I've been able to
 >>>>>> come up with it:
 >>>>>>
 >>>>>>       if a.count( targ ) == len(a):
 >>>>>>
 >>>>>> I'm somewhat afraid that this won't scale all that well. Am I 
missing
 >>>>>> something?
 >>>>>
 >>>>> a[1:] == a[:-1]
 >>>>>
 >>>>> :)
 >>>>>
 >>>>>
 >>>> Very clever! It is definitely the shortest solution.
 >>>
 >>> would that still not return true if the list was a palindrome?
 >> ignore me, just tried & ok
 >>
 >
 > You were right the first time.  The above comparison should have been
 >
 >      a == a[::-1]
 >
 > A palindrome will pass.

Let's find out (vertical space added for clarity):

     Python 3.7.2 (default, Dec 29 2018, 21:15:15)
     [GCC 8.2.1 20181127] on linux
     Type "help", "copyright", "credits" or "license" for more information.

     >>> a = [1, 1, 1, 1, 1]
     >>> a[1:] == a[:-1]
     True
     >>> a == a[::-1]
     True

     >>> a = [1, 2, 3, 4, 3, 2, 1]
     >>> a[1:] == a[:-1]
     False
     >>> a == a[::-1]
     True

Looks like Peter's pretty clever after all.  :-)

Dan