读取文件时python unpickling EOFError

Question

我编写了一个基本的存储类，它将数据保存在列表列表中，然后将其写入文件，然后允许从文件中读回以保持持久性。它在最初编写的系统（windows 7）上运行，我将它移到第二个系统（windows 8），现在它似乎出现故障。

我收到的错误是：

Traceback (most recent call last):
File "D:\Code Vault\pydb.py", line 69, in <module>
print Users.ReadData()
File "D:\Code Vault\pydb.py", line 23, in ReadData
self.data = cPickle.load(self.Inputstream)
EOFError

类的完整代码如下

class table():

    #TODO Insert Key Feild to facilitate ID Search 

    def __init__(self,*args):
        self.tablename = args[0]
        self.data = []
        self.colnames = {}
        self.filename = str(self.tablename)+ ".p"

        for e in args[1:]:
            self.colnames.update({e:len(self.colnames)})

        self.Filestorage = open(self.filename, "wb" )
        self.Filestorage.close()

    def ReadData(self):

        self.Inputstream = open(self.filename, "rb")
        self.Inputstream.seek(0)
        self.data = cPickle.load(self.Inputstream)
        self.Inputstream.close()
        return self.data

    def AddData (self, *args):
        self.tempdata = []

        for e in args:
            self.tempdata.append(e)
        if len(args) == len(self.colnames):
            self.data.append(self.tempdata)
        else:
            return "Incorrect argument quantities"
        return self.tempdata


    def Commit(self):
        self.Outputstream = open(self.filename, "ab" )
        cPickle.dump(self.data, self.Outputstream)
        self.Outputstream.close()
        return self.ReadData()

    def Search(self,query):
        for e in self.ReadData():
            if query in e:
                return self.ReadData().index(e)
        else:
            return "Value " + str(query) + " does not exist"

    def Update(self,query, edit):
        for e in self.data:
            if query in e:
                e[e.index(query)] = edit
        return self.data

    def DumpTable(self):
        self.data = []
        self.Outputstream = open(self.filename+".p", "wb" )
        cPickle.dump(self.data, self.Outputstream)
        self.Outputstream.close()
        self.ReadData()

Users = table("Users","Username","Password")
Users.AddData("bob","123456")
# Users.Commit()
# print Users.data
# print Users.filename
# print Users.data
print Users.ReadData()

这可能是代码盲目的情况，因为它以前工作过。任何想法将不胜感激

Answer 1

回答问题的修改后的代码。

import pickle

class table():

    #TODO Insert Key Feild to facilitate ID Search 

    def __init__(self,*args):
        self.tablename = args[0]
        self.data = []
        self.colnames = {}
        self.filename = str(self.tablename)+ ".p"

        for e in args[1:]:
            self.colnames.update({e:len(self.colnames)})

        try:                                      #creating this conditional prevented the contents being erased upon instantiating the class
            f = open(self.filename,"rb")
        except IOError:
            self.createfile = open(self.filename, "wb" )
            self.createfile.close()

    def ReadData(self):
        self.Inputstream = open(self.filename, "rb")
        self.data = pickle.load(self.Inputstream)
        self.Inputstream.close()
        return self.data

    def AddData (self, *args):
        self.tempdata = []

        for e in args:
            self.tempdata.append(e)
        if len(args) == len(self.colnames):
            self.data.append(self.tempdata)
        else:
            return "Incorrect argument quantities"
        return self.tempdata

    def Commit(self):
        self.Outputstream = open(self.filename, "wb" )
        pickle.dump(self.data, self.Outputstream)
        self.Outputstream.close()

    def createfile(self):
        self.createfile = open(self.filename, "wb" )
        self.createfile.close()

    def Search(self,query):
        for e in self.ReadData():
            if query in e:
                return self.ReadData().index(e)
        else:
            return "Value " + str(query) + " does not exist"

    def Update(self,query, edit):
        for e in self.data:
            if query in e:
                e[e.index(query)] = edit
        return self.data

    def DumpTable(self):
        self.data = []
        self.Outputstream = open(self.filename+".p", "wb" )
        pickle.dump(self.data, self.Outputstream)
        self.Outputstream.close()
        self.ReadData()

Answer 2

解决方案似乎在这里pickle.load() raising EOFError in Windows

即文件需要打开以在带有“rb”标志的二进制模式下读取。