patching random.choice in each run for a test case

Sorry that the question is not descriptive.

My problem is , I have a function that loops over a certain no. of times and picks a random element from a list each time. The problem is while writing testcase for this.

Sample code

def func(given):
    combo = [filled by a function]
    for i in range(0,given):
        com = random.choice(combo)

and my test case is like

@patch('random.choice',2)
def test_func():
    func(250)
    assert(expected,actual)

so when the test case runs , I want to dynamically give different value in each run for random.choice.

how can this be achieved ?

thanks in advnace