Pythonic way to check if: all elements evaluate to False -OR- all elements evaluate to True

Question

I want the results of the function to be:

• All values evaluate to False (None, 0, empty string) -> True
• All values evaluate to True -> True
• Every

Answer 1

def AllTheSame(iterable):
    return any(iterable) is all(iterable)

Answer 2

def unanimous(it):
  it1, it2 = itertools.tee(it)
  return all(it1) or not any(it2)

Answer 3

Piggybacking on Ignacio Vasquez-Abram's method, but will stop after first mismatch:

def unanimous(s):
  it1, it2 = itertools.tee(iter(s))
  it1.next()
  return not any(bool(a)^bool(b) for a,b in itertools.izip(it1,it2))

While using not reduce(operators.xor, s) would be simpler, it does no short-circuiting.

Answer 4

Not so brief, but shortcuts without messing around with 'tee' or anything like that.

def unanimous(s):
   s = iter(s)
   if s.next():
       return all(s)
   else:
       return not any(s)

Answer 5

def all_equals(xs):
    x0 = next(iter(xs), False)
    return all(bool(x) == bool(x0) for x in xs)

Answer 6

def all_bools_equal(lst):
    return all(lst) or not any(lst)

See: http://docs.python.org/library/functions.html#all

See: http://docs.python.org/library/functions.html#any