Pythonic method of determining if a list's contents change from odd to even values

Question

Writing some test cases and my mind wanders, assuming there is a better way to write something like this. I have a list, its numbers transition from all odd values to all even, doesn't matter where. I need to assert this is the case, here's what I came up with:

values = [1, 3, 5, 7, 5, 3, 5, 3, 5, 7, 4, 6, 8, 4, 2, 2, 8, 6]

# find all the indexes of odd and even values
odds = [i for (i, v) in enumerate(values) if v % 2 == 1]
evens = [i for (i, v) in enumerate(values) if v % 2 == 0]

# indexes should be a continuous sequence: 0, 1, 2, 3 ... n
assert odds + evens == range(evens[-1] + 1)

Seems like a long way to go. Suggestions on how this could be reduced?

Answer 1

A possible solution is to consider that you allow only

odd->odd
odd->even
even->even

in other words the only forbidden transition is

even->odd

and this translates to

(0, 1) not in ((x%2, y%2) for x, y in zip(values, values[1:]))

Answer 2

[x for x in values if x % 2 == 1] + [x for x in values if x % 2 == 0] == values

This is only true, if values starts with all of it's own odd values, followed by all of its even values.