On Tue, Jan 8, 2019 at 1:03 PM Skip Montanaro <skip.montan...@gmail.com> wrote: > > > > > > if len(a) == 0 or all(i == a[0] for i in a[1:]): > > > > > You don't need to check the length of the list because if the list is > > empty, 'all' will return True anyway. > > > > Given the structure of the expression passed as an argument to all(), won't > you get an IndexError if a is empty without the guard? > > (Would try it out if I had an interpreter on my phone...)
No, because the iteration would never happen. If the list is empty, a[1:] is also empty, and i==a[0] will never be evaluated. So it is safe. (But I agree that it's not instantly obvious.) ChrisA -- https://mail.python.org/mailman/listinfo/python-list
