在Python中生成实例列表

Question

我想从足球运动员那里拿一份名单（其名称，目标，俱乐部......等属性很少）并将它们添加到他们的俱乐部（这是另一个类别），但似乎我遗漏了一些东西因为俱乐部的球员名单在循环中正在改变，即使它没有被召唤（我认为我没有正确管理球员的实例）。

所以，这是代码：

clubsWithGoal = []

class Player:
nickname = ""
imageURL = ""
numberOfGoal = 0
clubId = ""

def __init__(self, nickname, imageURL, clubId, numberOfGoal = 0):
    self.nickname = nickname
    self.imageURL = imageURL
    self.clubId = clubId
    self.numberOfGoal = numberOfGoal

def __str__(self):
    return self.nickname


class Club:
Name = ""
ImageURL = u""
id = u""
numberOfGoal = 0
listOfPlayer = []

def __init__(self, id):
    del self.listOfPlayer [:]
    self.id = id
    self.getData()

def __str__(self):
    return self.Name

def getData(self):
    try:
        results = json.load(urllib.urlopen(
            "http://worldcup.kimonolabs.com/api/clubs/" + self.id + "?apikey={youwon'tseeit}"))
        self.ImageURL = results["logo"]
        self.Name = results["name"]
    except:
        print(self.id)

def addGoal(self, numberOfGoalsToAdd):
    self.numberOfGoal += numberOfGoalsToAdd

def addPlayer(self, player):
        self.listOfPlayer.append(player)
        print("added "+player.nickname+" to "+self.Name)
        self.addGoal(player.numberOfGoal)
        print("added the "+str(player.numberOfGoal)+" of "+player.nickname+" to "+self.Name)

所以这里是模型类，这里是必须对玩家进行排序而不起作用的函数：

def createAndOrderInClub(playerlist):
foundHisClub = False
for player in playerlist:
    for club in clubsWithGoal:
        # Case 1: The club already exists and the player is part of the club
        if player.clubId == club.id:
            club.addPlayer(player)
            foundHisClub = True
            break
    # Case 2: The club doesn't already exist
    if (foundHisClub == False):
        newclub = Club(player.clubId)
        newclub.addPlayer(player)
        clubsWithGoal.append(newclub)

这是一个在循环内部发生变化的例子（我是java开发人员，也是Python的新手）：

Answer 1

listOfPlayer容器，正如您声明的那样，是一个＆＃34;类变量＆＃34; （有点像java中的静态类成员），并且由于列表是可变的，因此无论何时在Club的任何实例中修改此列表，它都将针对所有实例进行更改。

要修复它，只需将其从类定义中删除，然后在__init__函数中初始化列表（字符串不存在问题，因为它们是不可变的）：

class Club:
    Name = ""
    ImageURL = u""
    id = u""
    numberOfGoal = 0

    def __init__(self, id):
        self.listOfPlayer = []      
        self.id = id
        self.getData()

Answer 2

listOfPlayer = []

这是一个类属性，意味着它为Club类的所有实例共享。如果您来自Java，您可以将其视为静态类变量。要使此列表对每个Club类都唯一，请确保在构造函数中使用self前缀对其进行初始化。

def __init__(self, id):
    del self.listOfPlayer [:]
    self.id = id
    self.listOfPlayer = []
    self.getData()

确保对您在课程级别定义的所有其他变量执行相同的操作：

Name = ""
ImageURL = u""
id = u""
numberOfGoal = 0

删除它们，并使用self在构造函数中初始化它们。

Answer 3

我认为问题是listOfPlayer类中的Club变量被声明为静态类成员，并且未在__init__函数内初始化。此演示 http://dbgr.cc/R 证明了这一点。

除了上述错误之外，您似乎还没有将循环内的foundHisClub变量重置为False。我会在第一个for循环中声明foundHisClub变量：

def createAndOrderInClub(playerlist):
    for player in playerlist:
        foundHisClub = False
        for club in clubsWithGoal:
            # Case 1: The club already exists and the player is part of the club
            if player.clubId == club.id:
                club.addPlayer(player)
                foundHisClub = True
                break
        # Case 2: The club doesn't already exist
        if (foundHisClub == False):
            newclub = Club(player.clubId)
            newclub.addPlayer(player)
            clubsWithGoal.append(newclub)