为何areas列表各元素href数据重复，id和name却能正确区分？

原因分析 #

核心问题是浅拷贝导致的可变对象引用复用：

• 你用areaInfo = dict(areaDict)做的是浅拷贝操作。对于字典里的不可变值（比如字符串类型的id、name），浅拷贝会直接复制值；但对于urls对应的嵌套列表这种可变对象，浅拷贝只会复制列表的内存引用，而非创建新的列表实例。
• 循环中所有areaInfo['urls']其实都指向同一个列表对象，每次修改areaInfo['urls'][0][1]都是在修改同一块内存里的内容，最终所有元素的urls都会被最后一次循环的赋值覆盖。
• 而id和name是不可变类型，每次赋值都会生成新的独立对象，不会共享引用，所以能正确区分不同项。

修复方案 #

方案1：手动初始化urls，避免引用复用 #

在循环内创建areaInfo时，重新初始化urls，不再复用模板字典里的列表引用：

areaDict = {
    "id": "",
    "name": "",
}
areas = []

def getCouncils():
    page = requests.get('https://profile.id.com.au/')
    soup = BeautifulSoup(page.content, 'html.parser')

    links = soup.select("a.councilCard")
    
    id = 0
    for anchor in links:
        areaInfo = dict(areaDict)
        areaInfo['id'] = id
        id += 1
        areaInfo['name'] = anchor.text.strip()
        # 手动创建新的urls列表，避免引用复用
        areaInfo['urls'] = [["profileID", anchor['href']], ["", ""]]
        areas.append(areaInfo)

方案2：使用深拷贝复制整个字典 #

通过copy.deepcopy实现完全拷贝，包括嵌套层级的所有可变对象：

import copy

areaDict = {
    "id": "",
    "name": "",
    "urls": [["", ""], ["", ""]],
}
areas = []

def getCouncils():
    page = requests.get('https://profile.id.com.au/')
    soup = BeautifulSoup(page.content, 'html.parser')

    links = soup.select("a.councilCard")
    
    id = 0
    for anchor in links:
        # 深拷贝复制所有层级的对象，避免引用共享
        areaInfo = copy.deepcopy(areaDict)
        areaInfo['id'] = id
        id += 1
        areaInfo['name'] = anchor.text.strip()
        areaInfo['urls'][0][0] = "profileID"
        areaInfo['urls'][0][1] = anchor['href']
        areas.append(areaInfo)

方案3：直接在循环内构造新字典 #

抛弃模板字典，每次循环直接创建独立的areaInfo，逻辑最直观：

areas = []

def getCouncils():
    page = requests.get('https://profile.id.com.au/')
    soup = BeautifulSoup(page.content, 'html.parser')

    links = soup.select("a.councilCard")
    
    id = 0
    for anchor in links:
        areaInfo = {
            "id": id,
            "name": anchor.text.strip(),
            "urls": [["profileID", anchor['href']], ["", ""]]
        }
        id += 1
        areas.append(areaInfo)

内容的提问来源于stack exchange，提问作者AlohaAbar