在 Python 的 while 循环中调用 function 及其先前的返回值作为参数

Question

I need to keep calling the following function with its previous return value as an argument in a while loop:

def announce_lead_changes(last_leader=None):
    """Return a commentary function that announces lead changes.

    >>> f0 = announce_lead_changes()
    >>> f1 = f0(5, 0)
    Player 0 takes the lead by 5
    >>> f2 = f1(5, 12)
    Player 1 takes the lead by 7
    >>> f3 = f2(8, 12)
    >>> f4 = f3(8, 13)
    >>> f5 = f4(15, 13)
    Player 0 takes the lead by 2
    """
    def say(score0, score1):
        if score0 > score1:
            leader = 0
        elif score1 > score0:
            leader = 1
        else:
            leader = None
        if leader != None and leader != last_leader:
            print('Player', leader, 'takes the lead by', abs(score0 - score1))
        return announce_lead_changes(leader)
    return say

I understand how the doctest works but how do I implement this in a while loop? I tried the following but it keeps on passing the default argument throughout loop:

commentary = both(say_scores, announce_lead_changes())
while
    ...
    commentary(score0, score1)

Answer 1

Update commentary for each iteration in the while loop. Try:

commentary = both(say_scores, announce_lead_changes())
while
    ...
    commentary = commentary(score0, score1)