Understand goless.select from the sample code

I have discovered python implementation of Goroutines, https://goless.readthedocs.org/en/latest/ and having a play

Given the following code from the documentation:

c1 = goless.chan()
c2 = goless.chan()

def func1():
    time.sleep(1)
    c1.send('one')
goless.go(func1)

def func2():
    time.sleep(2)
    c2.send('two')
goless.go(func2)

for i in range(2):
    case, val = goless.select([goless.rcase(c1), goless.rcase(c2)])
    print(val)

And it prints:

one
two

Documentation about the select method
> Select the first case that becomes ready. If a default case
> (goless.dcase) is present, return that if no other cases are ready. If
> there is no default case and no case is ready, block until one becomes
> ready.

So I went ahead and change the sleep(1) to sleep(3) as below:

c1 = goless.chan()
c2 = goless.chan()

def func1():
    time.sleep(3)
    c1.send('one')
goless.go(func1)

def func2():
    time.sleep(2)
    c2.send('two')
goless.go(func2)

for i in range(2):
    case, val = goless.select([goless.rcase(c1), goless.rcase(c2)])
    print(val)

And I thought it would print:

two
one

But it printed:

one
two

Why is that?

Since there is no answer so I went to have a dig on the project repo, found a similar question here:

https://github.com/rgalanakis/goless/issues/42

Most notable:

> using time.sleep just pauses the current thread. It does not do any switching between coroutines. You would have to use gevent.sleep or a similar mechanism for Stackless (or goless.backend.yield).

So it seemed that I misunderstood the goless would create different threads but I was wrong.