インスタンスの印刷と書式設定

Question

私はこのクラスのstrメソッドをここで定義しようとしています。これにより、クラスのインスタンスが印刷されるときに、My name is ___という形式のものが印刷されます。私は大学で何年も働いており、私は__プログラムを書いています。正しいフレーズの下には印刷されていますが、正しい値は印刷されません。どんな助けもありがとう。

class Student(): 
def __init__(self, name, years_at_umich=1): 
    self.name = name 
    self.years_UM = years_at_umich 
    self.bonus_points = random.randrange(1000) 
    self.programs_written = 0 
def __str__(self): 
    return "My name is %s. I've been in college for %d years and I've written %d programs" \ 
     %(self.name, self.years_UM, self.programs_written) 
def shout(self, phrase_to_shout): 
    print phrase_to_shout 

def year_at_umich(self): 
    return self.years_UM 

def write_programs(self, progs=1): 
    self.programs_written += progs 
    return self.programs_written 

---

***切り抜いた値のテスト、現在はそれが唯一の学生のための最後のテストに合格だ4 ********

あなたは方法 __str__を実装する必要が

class Student_test(unittest.TestCase): 
    def test_student1(self): 
     student1 = Student("Lyra") 
     self.assertEqual(student1.__str__(),"My name is Lyra. I've been at UMich for 1 years and I've written 0 programs.") 
    def test_student2(self): 
     student2 = Student("Aisha") 
     student2.write_programs() 
     self.assertEqual(student2.__str__(),"My name is Aisha. I've been at UMich for 1 years and I've written 1 programs.") 
    def test_student3(self): 
     student3 = Student("Ali",3) 
     student3.write_programs(4) 
     self.assertEqual(student3.__str__(),"My name is Ali. I've been at UMich for 3 years and I've written 4 programs.") 
    def test_student4(self): 
     student4 = Student("Aja") 
    student4.write_programs(12) 
    self.assertEqual(student4.programs_written, 12) 
    student4.write_programs() 
    self.assertEqual(student4.programs_written,13) 

Answer 1

を返します。役に立つかもしれません。例えば

：

>>>test_stu = Student("Mike") 
>>>print test_stu 

My name is Mike. I've been in college for 1 years and I've written 0 programs 

をそして、以下のリンクが役に立つことがあります：あなたが学生を印刷するとき

import random 
class Student(): 
    def __init__(self, name, years_at_umich=1): 
     self.name = name 
     self.years_UM = years_at_umich 
     self.bonus_points = random.randrange(1000) 
     self.programs_written = 0 

    def __str__(self): 
     return "My name is %s. I've been in college for %d years and I've written %d programs" \ 
      %(self.name, self.years_UM, self.programs_written) 

、あなたが表示されます

https://docs.python.org/2.7/reference/datamodel.html?highlight=mro#object.str と Difference between str and repr in Python

Answer 2

か__repr__はクラスStudentです。あなたは自分のやり方で印刷するインスタンスが必要な場合は、__str__は十分です：

def __str__(self): 
     return "My name is {}. I've written {} programs".format(self.name, self.programs_written) 

Answer 3

あなたは、インスタンスを文字列に変換されるたびに呼び出され、クラスの__str__方法、定義することによってこれを行うことができます。

を私が正しくあなたを理解していれば

class Student(): 
    # insert the same init here 

    def shout(self): # we do not need to ask for name because 
         # we already have it stored in self.name 
     phrase = "My name is %." 
     return phrase % self.name # format the text before returning it 
     # it's also useful to return the string instead 
     # of immediately printing it in this case because 
     # we will use it later 

    def year_at_umich(self): 
     phrase = "I've been at umich for %s years" # do not modify the instance attribute 
     return phrase % self.years_UM # use it to format your phrase 

    def say_number_programs(self): # keeping in pattern with our previous methods 
     phrase = "I've written %s programs" 
     return phrase % self.programs_written 

    def __str__(self): 
     return '%s. %s and %s.' % (self.shout(),    # we can format the final string 
            self.year_at_munich(),  # during the str call 
            self.say_number_programs) 

st = Student('Bob') 

print st 

これは、__str__()

My name is Bob. I've been at umich for 1 year and I've written 0 programs.

Answer 4

class Student(): 
    def shout(num, word): 
    if num == 1: 
     phrase = "My name is %s" % word 
    elif num == 2: 
     phrase = "I love %s" % word 
    elif num == 3: 
     phrase = "My favorite food is %s" % word 
    return phrase 

    def years(num): 
    phrase = "I've been at umich for %s years" % num 
    return phrase 

    def programs(num): 
    phrase = "I've written %s programs" % num 
    return phrase 

Student.shout（1、 'マッド'）