python unbound方法再次

Question

这让我陷入困难时期（对不起，我还是很新的python） 谢谢你的任何帮助。

错误

print Student.MostFrequent() TypeError: unbound method 

MostFrequent（）必须与 学生例如被称为第一个参数 （什么都没有代替）

这Student.MostFrequent（）被调用所有方式在最后（最后一行）和高清是最后清晰的类

编辑 - 命名修道院离子

我的长码

import csv 
class Student: 
    sports = [] 
    ftopics = [] 
    stopics = [] 
    choice_list = [] 
    choice_dict = {} 
    def __init__(self, row): 
     self.lname, self.fname, self.ID, self.gender, self.sport, self.movie, self.movieyr, self.country, self.ftopic, self.stopic = row 
     self.sports.append(self.sport) 
     self.ftopics.append(self.ftopic) 
     self.stopics.append(self.stopic) 
    def print_information(self): 
     return (self.lname, self.fname, self.ID, self.gender) 
    def print_first(self): 
     return (self.lname, self.fname, self.sport) 
    def print_second(self): 
     return (self.lname, self.fname, self.movie, self.movieyr) 
    def print_third(self): 
     return (self.lname, self.fname, self.country) 
    def print_fourth(self): 
     return (self.lname, self.fname, self.ftopic, self.stopic) 
    def most_frequent(self): 
     for choice in self.choice_list: 
       self.choice_dict[choice] = self.choice_dict.get(choice, 0) + 1 
     self.mostFrequent = sorted([(v, k) for k, v in self.choice_dict.items()], reverse=True) 
     print self.mostFrequent 

reader = csv.reader(open('new_mondy_csc_data_revise.csv'), delimiter=',', quotechar='"') 
header = tuple(reader.next()) 
print "%-17s|%-10s|%-6s|%s" %header[:4] 
print "-" * 45 
students = list(map(Student, reader)) # read all remaining lines 
for student in students: 
    print "%-17s|%-10s|%-6s|%3s" % student.print_information() 

print "%-17s|%-10s|%s" %(header[0],header[1],header[4]) 
print "-" * 45 
for student in students: 
    print "%-17s|%-10s|%s" %student.print_first() 

print "%-17s|%-10s|%-16s|%s" %(header[0],header[1],header[5],header[6]) 
print "-" * 45 
for student in students: 
    print "%-17s|%-10s|%-16s|%s" % student.print_second() 

print "%-17s|%-10s|%s" %(header[0],header[1],header[7]) 
print "-" * 45 
for student in students: 
    print "%-17s|%-10s|%s" %student.print_third() 

print "%-17s|%-10s|%-15s|%s" %(header[0],header[1],header[8],header[9]) 
print "-" * 45 
for student in students: 
    print "%-17s|%-10s|%-16s|%s" % student.print_fourth() 

k = len(students)  
# Printing all sports that are specified by students 
for s in set(Student.sports): # class attribute 
    print s, Student.sports.count(s), round(((float(Student.sports.count(s))/k) *100),1) 

# Printing sports that are not picked 
allsports = ['Basketball','Football','Other','Baseball','Handball','Soccer','Volleyball','I do not like sport'] 
allsports.sort() 
for s in set(allsports) - set(Student.sports): 
    print s, 0, '0%' 
Student.choice_list = Student.sports 
X = Student() 
X.most_frequent() 

#class Search(Student): 
# def __init__(self): 
#  Student.__init__ 

Answer 1

使用Student().MostFrequent()

编辑：

提防您使用类属性，这是很危险的。这里举一个例子：

>>> class Person: 
... name = None 
... hobbies = [] 
... def __init__(self, name): 
... self.name = name 
... 
>>> a = Person('marco') 
>>> b = Person('francesco') 
>>> a.hobbies.append('football') 
>>> b.hobbies 
['football'] 
>>> a.name 
'marco' 
>>> b.name 
'francesco' 
>>> a.name = 'mario' 
>>> b.name 
'francesco' 
>>> a.name 
'mario' 
>>> 

正如你所看到的我修改marco的爱好和francesco的爱好被修改后必然。

Answer 2

你们班闪避，方法定义

def MostFrequent(self,mostFrequent): 

有额外的变量mostFrequent，你可能不希望在那里。尝试更改为：

def MostFrequent(self): 

Answer 3

你很少调用一个类定义的方法（Student）

几乎总是创建类的实例

someStudent = Student(someRow) 

然后你调用的方法实例（“对象”），someStudent。

someStudent.MostFrequent() 

Answer 4

第一命名惯例阅读PEP-8：

方法名称和实例变量

Use the function naming rules: lowercase with words separated by 
    underscores as necessary to improve readability. 

第二你是在类Student调用mostFrequest，而不是插件它的意义。改为在实例上使用该方法：

student = Student(row) 
student.MostFrequent() 

Answer 5

Student.MostFrequent表示您试图使用静态方法，而不是实例方法。所以你必须先调用Student（）来创建实例，然后调用MostFrequent（）。

P.S .:如果这不是某个神秘项目的一部分，我建议您遵循PEP 8并使用most_frequent作为方法名称。

Answer 6

首先，我建议只使用函数名称小写。

将使用MostFrequent的结果作为静态方法得到的结果。为此，您需要明确地传递一个Student的实例作为第一个参数。

如果直接调用Student的实例，该实例将作为第一个参数隐式传递。

考虑使用staticmethod装饰器来静态使用函数。

Answer 7

你可能想要的是定义most_frequent为classmethod：

@classmethod 
def most_frequent(cls): 
    for choice in cls.choice_list: 
     cls.choice_dict[choice] = cls.choice_dict.get(choice, 0) + 1 
    cls.mostFrequent = sorted([(v, k) for k, v in cls.choice_dict.items()], reverse=True) 
    return cls.mostFrequent