如何在不互相替换的情况下获得字典的多个值？

Question

def newRecord(record):
    record= {'name' : 'test'}
    students = int(input('How many students are in your class? '))
    tests = int(input('How many tests have you given? '))
    for name in range(students):
        record ['name'] = input('Please enter students name: ')
        for test in range(tests):
            record ['test'] = input('Please enter test score: ')
    print (record)

For example, depending on the user input, I am trying to get record to print out as shown below and also trying to get all the values for test to be saved under the names specified.

{'name' : ' sam', 'test':  '99','98','78'}
{'name' : 'john', 'test':  '92','68','70'}

or

{'sam': '99','98','78'}
{'john':'92','68','70'}

Answer 1

use list as your tags imply:

record['test'] = []
for test in range(tests):
    score = input('Please enter test score: ')
    record['test'].append(score)

Answer 2

You should keep a list as values for each of the dictionary key items where keys will be student names and list will contain the test scores. See an example below.

record= {}
students = int(input('How many students are in your class? '))
tests = int(input('How many tests have you given? '))
for name in range(students):
    name = input('Please enter students name: ')
    testScores = []
    for test in range(tests):
        testScores.append(input('Please enter test score: '))
    record[name] = testScores
print (record)

It outputs:

How many students are in your class? 2
How many tests have you given? 3
Please enter students name: Alex
Please enter test score: 80
Please enter test score: 75
Please enter test score: 95
Please enter students name: Mac
Please enter test score: 90
Please enter test score: 88
Please enter test score: 79
{'Alex': ['80', '75', '95'], 'Mac': ['90', '88', '79']}

Answer 3

I see a few problems here:

• Your record parameter is instantly overwritten by the method, which may lead to strangeness down the road
• You're attempting to encapsulate multiple values in a data structure which only handles key-value relationships
• You're not really taking advantage of a useful design element with Python - class abstraction .

My recommendations:

1. Create a class for Student s and have all of their information referencable in there.

    class Student(object): def __init__(self, name): self.name = name self.test_scores = [] 

   Here I'd recommend you define a suitable __str__() value, but I leave this as an exercise for the reader.

2. Create a list of records somewhere which is simply a list of students.

    students = [] 

3. Adjust your newRecord method to make use of the class (and rename it to better describe its purpose).

    def create_new_records(): students = int(input('How many students are in your class? ')) tests = int(input('How many tests have you given? ')) for i in range(students): student_name = input('Please enter students name: ') student = Student(student_name) for j in range(tests): student.test_scores.append(input('Please enter test score: ')) students.append(student) print(student) 

Answer 4

You can keep using a dictionary if you'd like:

def newRecord():
    record = {}
    students = int(input('How many students are in your class? '))
    for name in range(students):
        name = input('Please enter students name: ')
        test = input('Please enter test score: ')
        record[name] = test
    print(record)

This will log:

How many students are in your class? 3
Please enter students name: john
Please enter test score: 12
Please enter students name: mike
Please enter test score: 33, 45, 66
Please enter students name: otherjohn
Please enter test score: 9
{'john': '12', 'otherjohn': '9', 'mike': '33, 45, 66'}

Or you can do it in-place with:

for name in range(students):
    record[input('Please enter students name: ')] = input('Please enter test score: ')
print (record)

This will ask you for the test scores first though and then the name.