Question

我有一个python字典，下面是该字典的键的输出：

{
"dependencies": {
    "@date-io/date-fns": "^1.0.1",
    "@material-ui/core": "^1.4.0",
    "@material-ui/icons": "^1.0.0",
    "@rails/webpacker": "3.5",
    "assert": "^1.4.1",
    "axios": "^0.18.0",
    "babel-core": "^6.26.3",
    "babel-eslint": "8.2.5",
    "babel-polyfill": "^6.26.0",
    "babel-preset-react": "6.24.1",
    "bootstrap": "^4.2.1",
    "caniuse-lite": "^1.0.30000926",
    "classnames": "^2.2.6",
    "connected-react-router": "4.5.0",
    "crypto-js": "^3.1.9-1",
    "date-fns": "2.0.0-alpha.21",
    "eslint-config-prettier": "^3.3.0",
    "eslint-plugin-prettier": "^3.0.0",
    "final-form": "^4.11.0",
    "history": "^4.7.2",
    "i18n-js": "3.1.0",
    "jquery": "3.3.1",
    "json-loader": "0.5.7",
    "json-stringify-safe": "^5.0.1",
    "lodash": "^4.17.11",
    "marked": "^0.6.0",
    "material-ui": "^0.20.2",
    "material-ui-pickers": "^2.1.0",
    "normalizr": "^3.3.0",
    "popper.js": "^1.14.6",
    "prettier": "^1.15.3",
    "promise-polyfill": "^8.1.0",
    "prop-types": "15.6.2",
    "query-string": "6.2.0",
    "ra-core": "^2.5.2",
    "ra-language-german": "^2.1.1",
    "ramda": "^0.26.1",
    "react": "^16.6.3",
    "react-admin": "^2.1.4",
    "react-cookie": "^3.0.8",
    "react-cookie-consent": "^2.0.0",
    "react-dom": "16.4.1",
    "react-final-form": "^3.7.0",
    "react-redux": "5.1.1",
    "react-router": "^4.3.1",
    "react-router-dom": "^4.3.1",
    "react-scrollchor": "^6.0.0",
    "recompose": "^0.30.0",
    "redux": "^4.0.1",
    "redux-form": "^7.4.2",
    "redux-persist": "^5.10.0",
    "redux-saga": "^0.16.2",
    "redux-thunk": "^2.3.0",
    "reselect": "^4.0.0",
    "svg-sprite-loader": "^3.8.0",
    "webpack": "^3.12.0",
    "whatwg-fetch": "^3.0.0",
    "yaml-loader": "0.5.0"
  },
  "devDependencies": {
    "dotenv": "^6.2.0",
    "enzyme": "3.8.0",
    "enzyme-adapter-react-16": "1.7.1",
    "enzyme-to-json": "3.3.5",
    "eslint": "5.11.1",
    "eslint-config-airbnb": "^17.1.0",
    "eslint-import-resolver-webpack": "^0.10.1",
    "eslint-plugin-import": "^2.14.0",
    "eslint-plugin-jsx-a11y": "^6.1.2",
    "eslint-plugin-react": "7.12.3",
    "expect": "^23.6.0",
    "jest": "23.2.0",
    "redux-mock-store": "^1.5.3",
    "stylelint": "^9.9.0",
    "stylelint-config-standard": "^18.2.0",
    "stylelint-declaration-use-variable": "^1.7.0",
    "stylelint-order": "^2.0.0",
    "webpack-dev-server": "2.11.2"
  },
}

我想将其中包含type(es_dict) <class 'dict'> type(es_dict.keys()) <class 'dict_keys'> es_dict.keys() dict_keys(['b_Biomass_Mid', <class 'oemof.solph.blocks.Bus'>, 'b_Coal_Mid', 'b_Gas_Mid', 'b_Lignite_Mid', 'b_Elec_Mid', 's_Biomass_Mid', <class 'oemof.solph.blocks.Flow'>, 's_Coal_Mid', 's_Gas_Mid', 's_Lignite_Mid', 'rs_Hydro_Mid', <class 'oemof.solph.blocks.InvestmentFlow'>, 'rs_Solar_Mid', 'rs_Wind_Mid', 'pp_Biomass_Mid', <class 'oemof.solph.blocks.Transformer'>, 'pp_Coal_Mid', 'pp_Gas_Mid', 'pp_Lignite_Mid', 'Elec_Mid', 'storage_Elec_Mid', 'b_Biomass_South', 'b_Coal_South', 'line_Mid_North', 'line_North_South', 'line_Mid_South'])的键收集到python列表中。

为此，我正在使用以下代码段：

'line'

但是我遇到以下错误：

list = []
for key in es_dict.keys():
    if 'line' in key:
        list.append(key)

该如何解决？

Answer 1

es_dict的某些键是类对象，不可迭代。您可以添加条件以确保键是字符串，然后再使用in运算符检查'line'是否为其子字符串：

if isinstance(key, str) and 'line' in key:

Answer 2

这与您的代码无关，而与dict的创建方式有关。字典中的某些键是 types / classes ，而不是实例。即<class 'oemof.solph.blocks.Bus'>

这很可能是一个错误。查看创建此映射的代码段。

从python字典获取某些键

2 个答案: