Question

我有一个dicts列表，我想删除所有dicts，其中几个特定键的值小于另一个dict中的对应值：

这是我的代码：

for d in clean_hosting_dicts:
    if (int(str(d["cores"]) ) < int(self.query["cores"]) ) or ( float(str(d["bandwidth"]).replace(",",".") ) < int(str(self.query["bandwidth"])) ) or ( float(str(d["storage"]).replace(",",".") ) < int(str(self.query["storage"])) ) or (float(str(d["ram"]).replace(",",".") ) < int(str(self.query["ram"])) ):
        del clean_hosting_dicts[clean_hosting_dicts.index(d)]

clean_hosting_dicts是我的dicts列表，而self.query是另一个dict，它具有相同的键但其他值可以测试它们。

这里是自我的json：

{"hosting_type" : "vps","cores": "3", "storage" :"2", "bandwidth" : "1", "ram" : "2", "ip" : "1"}

在此代码运行之前，这里是用于dicts列表的json（未过滤列表）：

[
  {
    "support_score": "4,5",
    "name": "Hostgator Snappy 8000",
    "ip": "2",
    "support": "chat,email,docs,phone,ticket",
    "ram": "8",
    "storage": "240",
    "frequency_rate": 3,
    "cpu": "AMD Opteron 6378",
    "reviews": "3",
    "bandwidth": "3",
    "domains": "1",
    "cores": "4",
    "os": "CentOS 66",
    "price": "39,95",
    "guarantee": "45"
  },
  {
    "support_score": "3,5",
    "name": "Bluehost Standard",
    "ip": "1",
    "support": "email,chat,doc,phone,ticket",
    "ram": "2",
    "storage": "30",
    "frequency_rate": 3,
    "cpu": "AMD Opteron 6378",
    "reviews": "3,2",
    "bandwidth": "1",
    "domains": "1",
    "cores": "2",
    "os": "CentOS 66",
    "price": "19,99",
    "guarantee": "30"
  },
  {
    "support_score": "3,5",
    "name": "Bluehost Enhanced",
    "ip": "2",
    "support": "email,chat,doc,phone,ticket",
    "ram": "4",
    "storage": "60",
    "frequency_rate": 3,
    "cpu": "AMD Opteron 6378",
    "reviews": "3,2",
    "bandwidth": "2",
    "domains": "1",
    "cores": "2",
    "os": "CentOS 66",
    "price": "29,99",
    "guarantee": "30"
  },
  {
    "support_score": "3,5",
    "name": "Bluehost Ultimate",
    "ip": "2",
    "support": "email,chat,doc,phone,ticket",
    "ram": "8",
    "storage": "240",
    "frequency_rate": 3,
    "cpu": "AMD Opteron 6378",
    "reviews": "3,2",
    "bandwidth": "4",
    "domains": "1",
    "cores": "4",
    "os": "CentOS 66",
    "price": "59,99",
    "guarantee": "30"
  },
  {
    "support_score": "4",
    "name": "iPage Business",
    "ip": "2",
    "support": "email,chat,doc,phone,ticket",
    "ram": "4",
    "storage": "90",
    "frequency_rate": 3,
    "cpu": "Unknown",
    "reviews": "3,7",
    "bandwidth": "3",
    "domains": "1",
    "cores": "2",
    "os": "CentOS 64",
    "price": "47,99",
    "guarantee": "30"
  },
  {
    "support_score": "4,5",
    "name": "InMotion vps-1000ha-s",
    "ip": "3",
    "support": "email, phone, skype, ticket,chat",
    "ram": "4",
    "storage": "75",
    "frequency_rate": 3,
    "cpu": "Unknown",
    "reviews": "4,5",
    "bandwidth": "4",
    "domains": "1",
    "cores": 5,
    "os": "CentOS 66",
    "price": "29,99",
    "guarantee": "30"
  },
  {
    "support_score": "4,5",
    "name": "InMotion vps-3000ha-s",
    "ip": "5",
    "support": "email, phone, skype, ticket,chat",
    "ram": "8",
    "storage": "260",
    "frequency_rate": 3,
    "cpu": "Unknown",
    "reviews": "4,5",
    "bandwidth": "6",
    "domains": "1",
    "cores": 5,
    "os": "CentOS 66",
    "price": "74,99",
    "guarantee": "30"
  },
  {
    "support_score": "4",
    "name": "Fatcow Business",
    "ip": "2",
    "support": "email,chat,doc,phone,ticket",
    "ram": "4",
    "storage": "90",
    "frequency_rate": 3,
    "cpu": "Unknown",
    "reviews": "3,8",
    "bandwidth": "3",
    "domains": "1",
    "cores": "2",
    "os": "CentOS 64",
    "price": "47,99",
    "guarantee": "30"
  },
  {
    "support_score": "4",
    "name": "1and1 Cloud L",
    "ip": "1",
    "support": "email,doc,phone,ticket",
    "ram": "2",
    "storage": "80",
    "frequency_rate": 3,
    "cpu": "Intel Xeon",
    "reviews": "3",
    "bandwidth": "0",
    "domains": "1",
    "cores": "2",
    "os": "CentOS 7",
    "price": "14,99",
    "guarantee": "30"
  },
  {
    "support_score": "4,5",
    "name": "Hostgator Snappy 2000",
    "ip": "2",
    "support": "chat,email,docs,phone,ticket",
    "ram": "2",
    "storage": "120",
    "frequency_rate": 3,
    "cpu": "AMD Opteron 6376",
    "reviews": "3",
    "bandwidth": "1,5",
    "domains": "1",
    "cores": "2",
    "os": "CentOS 64",
    "price": "19,95",
    "guarantee": "45"
  }
]

此代码运行后，删除所有不符合要求的词组，除了一个名称为1＆amp; 1 Cloud L＆＃34; ，这个有＆＃34; 2＆＃34;作为核心的值，query["cores"]是4，大于2（我将所有这些值转换为数字）

我不知道为什么它没有被删除，我无法通过pdb调试找到任何可以帮助在线的东西。

Answer 1

问题是您正在从正在迭代的列表中删除项目，因此我建议在不同的列表上进行迭代，例如使用表达式：

for d in clean_hosting_dicts[:]:
    ...

所以你迭代一个相等的列表，虽然不是同一个对象，只删除原始列表。

希望这有帮助！

Answer 2

列表推导可用于根据条件削减列表：

clean_hosting_dicts = [
    d for d in clean_hosting_dicts
    if not ((int(str(d["cores"])) < int(self.query["cores"])) or (
        float(str(d["bandwidth"]).replace(",", ".")) < int(
            str(self.query["bandwidth"]))) or (
        float(str(d["storage"]).replace(",", ".")) < int(
            str(self.query["storage"]))) or (
        float(str(d["ram"]).replace(",", ".")) < int(str(self.query["ram"]))))
]

在OP的代码中，在迭代时从列表中删除项目时会出现问题。上述方法可以工作，因为构建了一个新列表，然后将其分配回原始名称。

注意（从评论中）这将构建一个全新的对象，因此如果有人对原始列表有引用，那么该列表将不会更新。

为什么这个条件部分有效？

2 个答案: