Question

我一直在努力打造个人组织者。每天都会呈现为一个对象，其中包含在几个给定活动上花费的小时数。理想情况下，它还允许用户将此信息保存到文件并从以前的条目导入。

以下是代码：

class Day:

def __init__(self, date, hours, python, math, story, phil, medi):

    self.date = int(date)
    self.hours = float(hours)
    self.python = float(python)
    self.math = float(math)
    self.story = float(story)
    self.phil = float(phil)
    self.medi = float(medi)

def getDay(self):
    return repr((self.date, self.hours, self.python, self.math, self.story, self.phil, self.medi))

def getDayList(self):
    return list(self.date, self.hours, self.python, self.math, self.story, self.phil, self.medi)




def getInfo():

#the following allows the user to import an existing file with one object per line

question = input("Enter new information or import an existing file(new/imp)")

if question[0] == "i" or question[0] == "I":

    fileName = input("What is the name of the file you would like to import?")

    inFile = open(fileName, "r")



    dayList = []

    for line in inFile:

        dayList.append(line)

    print(dayList)


    return dayList


    inFile.close()



#the following allows the user to write objects to a new file or append objects to an existing file
#though I have not tested the latter feature

elif question[0] == "n" or question[0] == "N":

    question2 = input("Would you like to append this new info to an existing file or write it to a new file(a/w)? Hit blank ente to exit")
    fileName = input("Enter filename for new information")
    outFile = open(fileName, question2)

    dayList = []   
    while question2 != "":

        date = input("Please enter date (in single string)")
        hours = input("please enter total hours for the day")
        python = input("please enter total hours of python")
        math = input("please enter total hours of math")
        story = input("please enter total hours of story writing")
        phil = input("please enter total hours of philosophy")
        medi = input("please enter total hours of meditation")

        #creates object
        dayObject = Day(date, hours, python, math, story, phil, medi)
        dayList.append(dayObject)
        question2 = input("Would you ;like to enter more info now (enter 'yes' or hit blank enter to conclude)")

    #writes each object to the file
    for item in dayList:

        print(item, file=outFile)


    return dayList

    outFile.close()



def main():


dayList = getInfo()

test = dayList[0]

print(test)

print(test.getDay())


main()

当我创建一个新文件时，我可以在对象上使用方法：getDay（），例如，返回类的各个方面（日期，小时，python等）。但是，当我使用getInfo（）函数的前半部分中的代码导入相同的文件时，我收到此错误消息：

Traceback (most recent call last):
File "/Users/rainydaycart/Documents/po2.py", line 101, in <module>
main()
File "/Users/rainydaycart/Documents/po2.py", line 98, in main
print(test.getDay())
AttributeError: 'str' object has no attribute 'getDay'

当我打印新制作的对象时，它似乎是一个对象而不是一个字符串。当我从文件中导入相同的对象时，为什么我不能执行getDay（）方法，这是类定义的一部分？

P.S。使用函数头（模块？）在这篇文章中缩进似乎有点screwey，但是当我运行文件时它们不是问题。

Answer 1

当你做某事 -

for item in dayList:
    print(item, file=outFile)

你实际上并没有写对象，你只是为它写str(object)，而在你的情况下，由于你的班级没有定义__str__()或__repr__()，它会是写作 -

<__main__.Day object at 0x00260F10>

显示此内容的简单示例 -

>>> class CA:
...     pass
...
>>> with open('a.txt','w') as f:
...     print(c,file=f)
...

最后的文件包含 -

<__main__.CA object at 0x00260F10>

您实际想要使用的是 - pickle模块，用于对象序列化和反序列化。

然后，您可以使用pickle.dump()将对象写入文件，并使用 - pickle.load()加载。

示例 -

>>> class CA:
...     pass
...
>>> c = CA()
>>> c.x = 10
>>> import pickle
>>> with open('a.txt','wb') as f:
...     pickle.dump(c,f)
...
>>> del c
>>> with open('a.txt','rb') as f:
...     d = pickle.load(f)
...
>>> d
<__main__.CA object at 0x007150F0>
>>> d.x
10

Answer 2

在main()中，不应该是：

def main():
    object = Day()
    dayList = object.getInfo()
    test = dayList[0]

此外，您的outFile.close()和inFile.close()没有被击中，因为它们位于return()之后。

'str'对象没有属性 - 导入的文件对象无法识别其中一个方法？

2 个答案: