我收到一个``AttributeError：'int'对象没有属性'cityArray'`''

如何解决我收到一个``AttributeError：'int'对象没有属性'cityArray'`''

这是我代码的一部分，无论运行此代码时是否出现属性错误，我都打印了一些值，而不是仅仅出于检查目的而返回它们。我确实定义了cityArray，但是它仍然引发错误。

这基本上存储了CSV文件并进行线性搜索。

class City:#City classs
    def __init__(self,cid,cname,cstate,pop,cities):         #initilize the variables 

        self.cid= cid
        self.cname= cname                                  ##sets them all as empty lists
        self.cstate=cstate 
        self.pop= pop        
        self.cities= cities
        def __str__(self):                                  #return fuction to put out the final value
            print("cid: %s; cname: %s;cstate: %s; cases:%s"%(cid,cities))

class COV19Library:#library classs

    def __init__(self):
        self.issorted=False 
        self.cityArray=[]
        self.size=0

    def LoadData(self,filename: str):           #loads the data feom excel sheet into those empty lists
        file = csv.DictReader(open(filename))    #as it is in a directory everything is linked
        for temp in file:

            cid = temp["City_ID"]      #all the city ID
            pop = temp['POP10']        #the population
            cities = temp['6/30/20']   #the latest number of case

            t = temp['City State'].split()    #splits city and state

            cstate = [word for word in t if word.isupper()]    #A comprehension and a Bool to identify states
            cname = [x for x in t if x not in cstate]          #remove the states from the initial list and we get cities 
            #print(cname)           #test
        for r in range(len(cid)):
            self.cityArray.append(City(cid,cities))

    def linearSearch(self,city,attribute):                    #linear search algorythum
        #print(cid)

        if attribute == "name":
            for r in cname:
                if r == city:
                    print(r)
                else:
                    print("City not found")
        elif attribute=="id":
            for z in self.cid:
                if z == city:
                    print(z)
                else:
                    print("City not found")```


ERROR: 
Traceback (most recent call last):
  File "Proj.py",line 142,in <module>
    COV19Library.LoadData(0,'cov19_city.csv') 
  File "Proj.py",line 36,in LoadData
    self.cityArray.append(City(cid,cities))
AttributeError: 'int' object has no attribute 'cityArray'

解决方法

错误：

COV19Library.LoadData(0,'cov19_city.csv')

该调用将0作为第一个参数传递。此数字已分配给self，这会导致错误。

创建该类的实例并使用它：

covid = COV19Library()
covid.LoadData('a_file_name')

,

从错误回溯来看，似乎有错误的行是：

COV19Library.LoadData(0,'cov19_city.csv') 

从您的类中，我们可以看到LoadData接受了自身的一个实例以及csv文件的文件名。您将第一个参数传递为0，这将导致LoadData加载实例0，这将创建该int错误。

要解决此问题，您需要创建类的实例，例如：

library = COV19Library()
library.LoadData('cov19_city.csv')

我也可以问一下，为什么在同一函数中循环两次？如果放了，会不会更容易

self.cityArray.append(City(cid,cname,cstate,pop,cities))

紧接着

cname = [x for x in t if x not in cstate]

编辑：

class City:  # City classs
    def __init__(self,cid,cities):  # initilize the variables

        self.cid = cid
        self.cname = cname  # sets them all as empty lists
        self.cstate = cstate
        self.pop = pop
        self.cities = cities

        def __str__(self):  # return fuction to put out the final value
            print("cid: %s; cname: %s;cstate: %s; cases:%s" %
                (cid,cities))


class COV19Library:  # library classs

    def __init__(self):
        self.issorted = False
        self.cityArray = []
        self.size = 0

    def LoadData(self,filename: str):  # loads the data feom excel sheet into those empty lists
        # as it is in a directory everything is linked
        file = csv.DictReader(open(filename))
        for temp in file:

            cid = temp["City_ID"]  # all the city ID
            pop = temp['POP10']  # the population
            cities = temp['6/30/20']  # the latest number of case

            t = temp['City State'].split()  # splits city and state

            # A comprehension and a Bool to identify states
            cstate = [word for word in t if word.isupper()]
            # remove the states from the initial list and we get cities
            cname = [x for x in t if x not in cstate]
            # print(cname)           #test
            self.cityArray.append(City(cid,cities))

    def linearSearch(self,city,attribute):  # linear search algorythum
        # print(cid)

        for r in self.cityArray:
            if r.attribute == city:
                print(r)
            else:
                print("City not found")

要回答您的评论，请不断获取AttributeError：'COV19Library'对象没有属性'cname'

如果您查看COV19Library类的构造函数：

class COV19Library:  # library classs

    def __init__(self):
        self.issorted = False
        self.cityArray = []
        self.size = 0

cname不是此方法中的变量之一，因此它在库中不存在。不过，如果您调用City类的实例（这是cityArray存储的内容），则可以访问Cname。

知道这一点后，您可以遍历城市数组：

    def linearSearch(self,attribute):  # linear search algorythum
        # print(cid)

        for r in self.cityArray:
            if r.attribute == city:
                print(r)
            else:
                print("City not found")

要调用此方法，您可以执行以下操作：

library.linearSearch('TX',cstate)

让我们完成每个步骤：

1. 调用该函数时，它将接收COV19Library的当前实例，您要查找的值（字符串或整数）以及要传递的属性。（变量名）
2. 程序循环遍历您在LoadData（）中已经创建的city数组，每个循环变量称为r
3. 它比较r的属性，并查看您传入的值是否与r的属性值相同
4. 这会一直循环直到找到它，或者它不存在。