Question

我已经审核了很多其他帖子，但我确实理解您在迭代时不想修改列表。我仍然得到可怕的列表。删除（x）：x不在列表中＆＃39;很明显，我仍然试图修改一些我不应该修改的东西，只是无法弄清楚在哪里。

这里首先是函数的一部分，它调用函数执行工作并返回一个列表：

for inn in range(1,7):
    for pos in lstPositions:
    weight = 10
    posAssigned = 0
        while (posAssigned == 0):
            lstPlayers = getWeights(weight,pos,inn)

正如您所看到的，我希望获得返回值的玩家列表。现在这里是函数getWeights。正如您在第二部分中看到的，我首先将lstPlayersFunc复制到lstPlayersTmp并迭代lstPlayersTmp，修改lstPlayersFunc。我在下面粘贴的追溯显示了当我尝试从lstPlayersFunc中删除元素时的问题。

def getWeights(weight,pos,inn):
    lstPlayersFunc = []
    for player in positions:
        if positions[player][pos] == weight:
            lstPlayersFunc.append(player)

lstPlayersTmp = lstPlayersFunc[:]
for player in lstPlayersTmp:
    maxBench = 6 - positions[player]['MaxInn']
    for pos in lstPositions:
        if lineup[str(inn)][pos] == player:
            lstPlayersFunc.remove(player)
        elif positions[player]['MaxInn'] <= cntPos[player]['total']:
            lstPlayersFunc.remove(player)
        elif positions[player]['MaxPitch'] <= cntPos[player]['P']:
            lstPlayersFunc.remove(player)
        elif positions[player]['MaxCatch'] <= cntPos[player]['C']:
            lstPlayersFunc.remove(player)
        elif maxBench <= cntPos[player]['B']:
            lstPlayersFunc.remove(player)

return lstPlayersFunc

回溯：

Traceback (most recent call last):
File "./lineups4.py", line 126, in <module>
posAssign()
File "./lineups4.py", line 93, in posAssign
lstPlayers = getWeights(weight,pos,inn)
File "./lineups4.py", line 76, in getWeights
lstPlayersFunc.remove(player)
ValueError: list.remove(x): x not in list

Answer 1

您没有提供足够的代码来确定，但我猜测您多次删除相同的player。你的循环结构如下：

for player in lstPlayersTmp:
    maxBench = 6 - positions[player]['MaxInn']
    for pos in lstPositions:
        # A number of tests any one of which passing removes the player

问题是，如果您点击其中一个测试并且for pos in lstPositions:一个remove，则内部player循环不会终止。猜测时，两个不同的pos值导致通过测试，第二次，您尝试remove player已经消失了。

尝试在该循环中的每个break调用之后添加remove。毕竟，一旦玩家被remove编辑，您就不再关心他们，因此您可以停止检查新pos并转到下一个player。< / p>

即使复制列表，Python列表迭代/修改问题

1 个答案: