Question

我在更新嵌套的defaultdict中的列表时遇到问题。

这是我的代码：

a = ['20160115',    'shadyside medical building',   1, 'Review']
b = ['20160115',    'shadyside medical building',   1, 'Video']
c = ['20160215',    'shadyside medical building',   1, 'Video']
d = ['20160215',    'medical building',             1, 'Video']
f = [a,b,c,d]

nested_dict = defaultdict(dict)

for date,keyword,pos,feature in f:
    nested_dict[keyword].update({feature : [pos]})
    nested_dict[keyword].update({feature : [pos]})

这是输出：

{'shadyside medical building': 
                             {'Review': [1], 
                             'Video': [1]}, 
'medical building': 
                   {'Video': [1]}}

所需的输出是：

{'shadyside medical building': 
                             {'Review': [1], 
                             'Video': [1,1]}, 
'medical building': 
                   {'Video': [1]}}

请注意，视频的第二项已添加到视频列表中。

Answer 1

你没有嵌套任何defaultdict，所以这样做：

nested_dict = defaultdict(lambda: defaultdict(list))

和

nested_dict[keyword][feature].append(pos)

Answer 2

您还可以创建一个无限嵌套的defaultdict：

public static void main(String[] args) {
        Banking[] uaccounts;
        uaccounts = new Banking[100]; // setting up array
        int arrcount = 0; // setting counter for array
        int menu = 1;   // Creating a variable to loop menu
        while (menu == 1) {  //Creating the loop for the menu
            System.out.println("|=================================================|");     // drawing the menu
            System.out.println("|                                                 |");
            System.out.println("|                     MAIN MENU                   |");
            System.out.println("|  1. Create Account (BANK MANAGER RESTRICTED)    |");
            System.out.println("|  2. Check Account Balance                       |");
            System.out.println("|  3. Deposit Into Account                        |");
            System.out.println("|  4. Withdraw From Account                       |");
            System.out.println("|  5. Quit                                        |");
            System.out.println("|                                                 |");
            System.out.println("|=================================================|");

            int uinput = Integer.parseInt(JOptionPane.showInputDialog("Please select an option from above(1 - 4):"));
            if (uinput == 1) {    // initiating menu option 1
                String full_name = JOptionPane.showInputDialog("Please enter clients full name:");     // creating some variables
                String address = JOptionPane.showInputDialog("Please enter the clients address:");
                String password = JOptionPane.showInputDialog("Please enter the clients password:");
                int accid = RandomInt(100000, 999999);
                System.out.println("Customers Account ID:" + accid);
                double balance = Double.parseDouble(JOptionPane.showInputDialog("Please enter the client's starting balance:"));
                uaccounts[arrcount] = new Banking(full_name, address, accid, balance, password); // creating objectg in array
                arrcount = arrcount + 1; //adding to counter for next time

            }
            if (uinput == 2) {     // initiating menu option 2
                int acc_id_input = Integer.parseInt(JOptionPane.showInputDialog("Please enter your account ID:"));
                String password_input = JOptionPane.showInputDialog("Please enter your password:");
                int arrcount2 = arrcount - 1;
                LoginUser(acc_id_input, password_input, uaccounts, arrcount2);
            }





public static void LoginUser(int account_id, String password, Banking[] uaccounts, int arrcount) {
        boolean found = false;
        int accIndex = 0;
        for (int i = 0; i < arrcount - 1; i++) {
            if ((uaccounts[i].accid == account_id) && (uaccounts[i].password.equals(password))) {
                found = true;
                accIndex = i;
                break;
            } else {
                found = false;
            }
        }

Python中的嵌套Defaultdicts

2 个答案: