类或对象，而不是Python 2中的字典 [英] class or object instead of dictionaries in Python 2

问题描述

我通常使用嵌套字典，但我想转到类和对象。我有一份家庭工作成绩列表，如下所示：

  assignment_name assignment_subject student_name due_date grade grade_pct rank 
  

我想提出一个拥有所有学生的对象，每个学生都拥有所有的作业详细信息。我的字典看起来像：

 家庭作业['student_name'] ['assignment_name'] = {'assignment_subject'：' ，'due_date'：'11 / 12/13'，'grade'：15，'grade_pct'：15 / 20.0，'rank'：'B'} 
  

应该是一个类中的类吗？

  class Homeworks对象）：
 def _init_（self）：
 self.students 
 
类学生（对象）：
 def _init_（self，student_name）：
 self.student_name = student_name 
 
 def add_assignment（line）：
 student.assignment_name = line [0] 
 student.assignment_subject = line [1] 
 student.grade = line [4] 
  

我知道这是不对的。我不知道我是否在正确的轨道上。我需要能够访问一个学生的成绩。 （在作业中的作业['Robbie Michaels']。键（）：打印家庭作业['Robbie Michaels'] [作业] ['grade'] ）我也喜欢使用如果assignment_subject =='math'等访问它们。

解决方案

  class student：
 def __init __（self，student_name）：
 self.name = student_name 
 
 class homework：
 
 def __init __（self，student_name，assignment_name，assignment_subject，grade）：
 self.student = student（student_name）
 self.assignment_name = assignment_name 
 self.assignment_subject = assignment_subject 
 self.grade = grade 
 
 @classmethod 
 def new_hw（cls，line）：
 return cls（line [0]，line [1]，line [2]，line [3]）
 
 @classmethod 
 def get_all_grades（cls，student_name，homework_list）：
 return [x.grade for x in homework_list如果student_name是x.student.name] 
 
l ines = [[abc，a，b，A]，[abc，c，d，B]，[ebc，c ，B]] 
 hw_list = [homework.new_hw（line）for line in lines] 
 print homework.get_all_grades（abc，hw_list）
  

您需要了解的是如何设计面向对象？
上面的代码可能不是最好的设计，因此，尝试这个来学习从哪里开始。 如何在Python中设计类？

I normally use nested dictionaries, but I'd like to move into classes and objects. I have a list of home work grades that look like:

assignment_name assignment_subject student_name due_date grade grade_pct rank

I'd like to make an object that holds all the students and each students holds all of their assignments details. My dictionary would look like:

homeworks['student_name']['assignment_name'] = {'assignment_subject': 'math', 'due_date': '11/12/13', 'grade': 15, 'grade_pct': 15/20.0, 'rank': 'B'}

Should this be a class within a class?

class Homeworks(object):
    def _init_(self):
        self.students

    class student(object):
        def _init_(self,student_name):
             self.student_name = student_name

        def add_assignment(line):
             student.assignment_name = line[0]
             student.assignment_subject = line[1]
             student.grade = line[4]

I know this isn't right. I don't know if I am on the right track or not. I do need to be able to access the grades for one student. (for assignment in Homeworks['Robbie Michaels'].keys(): print Homeworks['Robbie Michaels'][assignment]['grade']) I also like to access them using if assignment_subject == 'math' etc.

解决方案

class student:
    def __init__(self, student_name):
        self.name = student_name

class homework:

    def __init__(self,student_name,assignment_name,assignment_subject,grade):
        self.student = student(student_name)
        self.assignment_name = assignment_name
        self.assignment_subject = assignment_subject
        self.grade = grade

    @classmethod
    def new_hw(cls, line):
        return cls(line[0],line[1],line[2],line[3])

    @classmethod
    def get_all_grades(cls, student_name, homework_list):
        return [ x.grade for x in homework_list if student_name is x.student.name]

lines = [["abc","a","b","A"],["abc","c","d","B"],["ebc","c","d","B"]]
hw_list = [homework.new_hw(line) for line in lines]
print homework.get_all_grades("abc",hw_list)

What you need to understand is "How to design Object-Orientedly?". The above code, may not be the best of designs, hence, try this to learn where to start. How do I design a class in Python?

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