81、测试类

在测试类的练习中，先编写了一个模块survey.py,模块中包含一个类AnonymousSurvey()

# -*- coding: utf-8 -*-
class AnonymousSurvey():
    """收集匿名调查问卷的答案"""

    def __init__(self,question):
        """存储一个问题，并为存储答案做准备"""
        self.question = question
        self.responses = []

    def show_question(self):
        """显示调查问卷"""
        print(self.question)

    def store_response(self,new_response):
        """存储单份调查问卷"""
        self.responses.append(new_response)

    def show_results(self):
        """显示收集的所有答案"""
        print("Survey result:")
        for response in responses:
            print("- " + response)

测试类language_survey:

from survey import AnonymousSurvey

# 定义一个问题，并创建一个表示调查的AnonymousSurvey对象
question = "What language did you first learn to speak?"
my_survey = AnonymousSurvey(question)

# 显示问题并存储答案
my_survey.show_question()
print("Enter 'q' at any time to quit.\n")
while True:
    response = raw_input("Language: ")
    if response == 'q':
        break
    my_survey.store_response(response)

# 显示调查结果
print("\nThank you to everyone who participated in the survey!")
my_survey.show_results()

结果一直报错：

D:\ProgramData\Anaconda2\python.exe F:/python/python_work/test/class/language_survey.py
What language did you first learn to speak?
Enter 'q' at any time to quit.

Language: Chinese
Language: English
Language: Spanish
Language: q

Thank you to everyone who participated in the survey!
Survey result:
Traceback (most recent call last):
  File "F:/python/python_work/test/class/language_survey.py", line 19, in <module>
    my_survey.show_results()
  File "F:\python\python_work\test\class\survey.py", line 21, in show_results
    for response in responses:
NameError: global name 'responses' is not defined

Process finished with exit code 1

运行结果显示报错，报错原因：global name 'responses' is not defined，意思是全局变量responses找不到，但我检查完代码，仍旧没发现错误，只好截图向大大请教。

大大指出我是在survey.py模块中的第21行for response in后面没加上 self.xxxxx 代码错误处

原来都是我的粗心大意导致的，同时也反映了我对类的基本定义并没有完全理解，我赶紧翻书查阅在类中self的定义。
self：在每个与类相关联的方法调用都自动传递实参self,它是一个指向实例本身的引用，让实例能够访问类中的属性和方法
在survey.py模块第21行代码中因为丢失形参self,导致没法传递实参responses的内容，所以结果会报错变量responses找不到。
我按照大大的提示修改了代码，结果能正常运行了
survey.py

# -*- coding: utf-8 -*-
class AnonymousSurvey():
    """收集匿名调查问卷的答案"""

    def __init__(self,question):
        """存储一个问题，并为存储答案做准备"""
        self.question = question
        self.responses = []

    def show_question(self):
        """显示调查问卷"""
        print(self.question)

    def store_response(self,new_response):
        """存储单份调查问卷"""
        self.responses.append(new_response)

    def show_results(self):
        """显示收集的所有答案"""
        print("Survey result:")
        for response in self.responses:
            print("- " + response)

测试类language_survey:

fromsurveyimportAnonymousSurvey

#定义一个问题，并创建一个表示调查的AnonymousSurvey对象
question="Whatlanguagedidyoufirstlearntospeak?"
my_survey=AnonymousSurvey(question)

#显示问题并存储答案
my_survey.show_question()
print("Enter'q'atanytimetoquit.\n")
whileTrue:
response=raw_input("Language:")
ifresponse=='q':
break
my_survey.store_response(response)

#显示调查结果
print("\nThankyoutoeveryonewhoparticipatedinthesurvey!")
my_survey.show_results()

运行结果：

What language did you first learn to speak?
Enter 'q' at any time to quit.

Language: Chinese
Language: English
Language: Spanish
Language: q

Thank you to everyone who participated in the survey!
Survey result:
- Chinese
- English
- Spanish

Process finished with exit code 0