如何从用户输入正确添加到字典并使用 for 循环打印字典？答案

【问题标题】：How do I properly add to a dict from user input and print the dict with a for loop?如何从用户输入正确添加到字典并使用 for 循环打印字典？
【发布时间】：2020-06-13 00:20:36
【问题描述】：

一段时间以来，我一直在尝试获取用户输入并将其添加到现有字典中。然后使用 for 循环打印字典键和值，但我无法弄清楚执行此操作的正确方法。

经过研究，我几乎可以肯定我没有正确地将用户输入的值添加到 dict 中，并且当代码运行时，我收到一条错误消息，指出“set”是可下标的。我应该如何将用户数据添加到字典并正确打印？

# Authorized Users
authorized_users = ["Jim","Mary","Claire","Hector","Ren"]

# Student Dictionary
students ={
    "Alice":{"id": "1", "age":26, "grade":"A"},
    "Bob":{"id": "2", "age":34, "grade":"C"},
    "Jimbo":{"id": "3", "age":12, "grade":"B"},
    "Karen":{"id": "4", "age":33, "grade":"D"},
    "Keith":{"id": "5", "age":53, "grade":"F"}
    }


while True:
    login = input("Please login with an authorized user: ").strip().title()

    if login in authorized_users:
        print("\nWelcome back "+login+", please choose an option from the menu!")

        print(
            '''
            1.) View Student List
            2.) View Authorized Users
            3.) Add student
            4.) Remove Student
            5.) Exit program
            '''
             )

        authorized_input = int(input("Select an option from the list above to proceed.: "))

        if authorized_input == 1:
            print("\n*** ACTIVE STUDENTS ***")
            for student_id, student_info in students.items():
                print("\nName:", student_id)
                for key in student_info:
                    print(key + ':', student_info[key])      
            print("\n")


        elif authorized_input == 2:
            print("\n*** AUTHORIZED USERS ***")
            for x in range(len(authorized_users)):
                print(authorized_users[x])

            print("\n")

        elif authorized_input == 3:
            print("Please fill in the new students information")

            student_name = input("Enter the student's name: ")
            student_id = input("Enter the student's ID: ")
            student_age = input("Enter the student's age: ")
            student_grade = input("Enter the student's grade: ")

            # Add data to dict students
            students[student_name] = {student_id, student_age, student_grade}

            for student_id, student_info in students.items():
                print("\nName:", student_id)
                for key in student_info:
                    print(key + ':', student_info[key])  
            print("\n")


        elif authorized_input == 4:
            print("option 4")

        elif authorized_input == 5:
            quit()

    else:
        print("access denied")

【问题讨论】：

标签： python python-3.x list dictionary

【解决方案1】：

您希望students 中的每个项目本身都是字典（因此students 是字典字典）。要做到这一点，你需要改变

students[student_name] = {student_id, student_age, student_grade}

类似

students[student_name] = {
    'id': student_id, 
    'age': student_age, 
    'grade': student_grade
}

正如目前所写，您正在创建 set {student_id, student_age, student_grade} 而不是 dict。

【讨论】：

【解决方案2】：

改成

students[student_name] = {student_id, student_age, student_grade}

这个

students[student_name] = {'id': student_id, 'age': student_age, 'grade': student_grade}

【讨论】：

【解决方案3】：

您需要为字典中的每个值提供正确的键：

students ={
    "Alice":{"id": "1", "age":26, "grade":"A"},
    "Bob":{"id": "2", "age":34, "grade":"C"},
    "Jimbo":{"id": "3", "age":12, "grade":"B"},
    "Karen":{"id": "4", "age":33, "grade":"D"},
    "Keith":{"id": "5", "age":53, "grade":"F"}
    }

student_name = 'DirtyBit'
student_id = '12345'
student_age = 22
student_grade = 'A'
students[student_name] = {'id': student_id, 'age': student_age, 'grade': student_grade}

print(students)

改变这个（这是一个set）：

students[student_name] = {student_id, student_age, student_grade}

对此（这是一个key-value配对dict）：

students[student_name] = {'id': student_id, 'age': student_age, 'grade': student_grade}

【讨论】：