Python - 向下迭代字典 - 有条件地向下移动树

Question

我下面有一些 python 代码，它沿着树走下去，但我希望它沿着树向下工作，检查根据值有条件地采取一些路径。我想LandedPrice根据条件获取树的分支fulfillmentChannel

parsed_results['LowestLanded'] = sku_multi_sku['Summary']['LowestPrices']['LowestPrice']['LandedPrice']['Amount']['value']

沿着这棵树走下去，但是值，因为有两个LowestPrice记录/字典为每个 condition和fulfillmentChannel 一对返回一个。我想过滤condition=new，fulfillmentChannel=Amazon所以我只得到一条记录。当我解析 XML 数据时，我可以使用类似于此处的代码来完成LowestPrices/LowestPrice[@condition='new'][@fulfillmentChannel='Merchant']/LandedPrice/Amount"此操作，但无法获得类似的代码来工作。我该如何用字典做到这一点？

 "LowestPrices":{
     "value":"\n                ",
     "LowestPrice":[
        {
           "value":"\n                    ",
           "condition":{
              "value":"new"               #condtion new
           },
           "fulfillmentChannel":{
              "value":"Amazon"            ## fulfilllmentChannel #1
           },
           "LandedPrice":{
              "value":"\n                        ",
              "CurrencyCode":{
                 "value":"USD"
              },
              "Amount":{
                 "value":"19.57"
              }
           },
           "ListingPrice":{
              "value":"\n                        ",
              "CurrencyCode":{
                 "value":"USD"
              },
              "Amount":{
                 "value":"19.57"
              }
           },
           "Shipping":{
              "value":"\n                        ",
              "CurrencyCode":{
                 "value":"USD"
              },
              "Amount":{
                 "value":"0.00"
              }
           }
        },
        {
           "value":"\n                    ",
           "condition":{
              "value":"new"
           },
           "fulfillmentChannel":{
              "value":"Merchant"
           },
           "LandedPrice":{
              "value":"\n                        ",
              "CurrencyCode":{
                 "value":"USD"
              },
              "Amount":{
                 "value":"19.25"
              }
           },
           "ListingPrice":{
              "value":"\n                        ",
              "CurrencyCode":{
                 "value":"USD"
              },
              "Amount":{
                 "value":"19.25"
              }
           },
           "Shipping":{
              "value":"\n                        ",
              "CurrencyCode":{
                 "value":"USD"
              },
              "Amount":{
                 "value":"0.00"
              }
           }
        }
     ]
  },

Answer 1

您可以将列表推导式与条件逻辑结合使用来达到您的目的，如下所示：

my_dict = {
    "LowestPrices": {
        "value": "\n                ",
        "LowestPrice": [{
            "value": "\n                    ",
            "condition": {
                "value": "new"
            },
            "fulfillmentChannel": {
                "value": "Amazon"
            },
            "LandedPrice": {
                "value": "\n                        ",
                "CurrencyCode": {
                    "value": "USD"
                },
                "Amount": {
                    "value": "19.57"
                }
            },
            "ListingPrice": {
                "value": "\n                        ",
                "CurrencyCode": {
                    "value": "USD"
                },
                "Amount": {
                    "value": "19.57"
                }
            },
            "Shipping": {
                "value": "\n                        ",
                "CurrencyCode": {
                    "value": "USD"
                },
                "Amount": {
                    "value": "0.00"
                }
            }
        },
            {
                "value": "\n                    ",
                "condition": {
                    "value": "new"
                },
                "fulfillmentChannel": {
                    "value": "Merchant"
                },
                "LandedPrice": {
                    "value": "\n                        ",
                    "CurrencyCode": {
                        "value": "USD"
                    },
                    "Amount": {
                        "value": "19.25"
                    }
                },
                "ListingPrice": {
                    "value": "\n                        ",
                    "CurrencyCode": {
                        "value": "USD"
                    },
                    "Amount": {
                        "value": "19.25"
                    }
                },
                "Shipping": {
                    "value": "\n                        ",
                    "CurrencyCode": {
                        "value": "USD"
                    },
                    "Amount": {
                        "value": "0.00"
                    }
                }
            }
        ]
    },
}

lowest_prices = [x for x in my_dict["LowestPrices"]["LowestPrice"] if
                 x["condition"]["value"] == "new"
                 and x["fulfillmentChannel"]["value"] == "Amazon"]

lowest_prices是满足所需条件的所有字典的列表。如果您确定您的情况下只有一个字典满足条件，或者您只想获取第一个字典的数量，您只需执行以下操作：

if len(lowest_prices) > 0:
    amount = lowest_prices[0]["LandedPrice"]["Amount"]["value"]
    print(amount)