CODEWITHSUNDEEP
python-3.xfile-iopickle
user1547462
user1547462

Reputation:

Unpickled object does not match original

My program fails to unpickle my data, where pickle.load(f) does not match pickle.dump(object,f). My question is where am I going wrong with the following code, as I have experimented with various file modes with the corresponding errors listed above my code below:

f = open(home + '/.GMouseCfg','ab+')

out: They are different

f = open(home + '/.GMouseCfg','ab+', encoding='utf-8')

ValueError: binary mode doesn't take an encoding argument

f = open(home + '/.GMouseCfg','a+')

TypeError: must be str, not bytes

import abc, pprint
from evdev import ecodes as e
from os.path import expanduser

try:
    import cPickle as pickle
except:
    import pickle


class Command(object):
    __metaclass__ = abc.ABCMeta

    @abc.abstractmethod
    def set(self, data):
        """set data used by individual commands"""
        return

    @abc.abstractmethod
    def run(self):
        """implement own method of executing data of said command"""
        return

class KeyCommand(Command):
    def __init__(self, data):
        self.data = data
    def set(data):
        self.data = data
    def run(self):
        pass
    def __str__(self):
        return data

class SystemCommand(Command):
    def __init__(self, data):
        self.data = data
    def set(data):
        self.data = data
    def run(self):
        pass
    def __str__(self):
        return data

if __name__ == '__main__':
    ids = [2,3,4,5,6,7,8,9,10,11,12]
    home = expanduser('~')
    f = open(home + '/.GMouseCfg','a+')
    f.seek(0)

    commands = list()
    commands.append(KeyCommand({3:[e.KEY_RIGHTCTRL,e.KEY_P]}))
    commands.append(SystemCommand({5:['gedit','./helloworld.txt']}))
    pickle.dump(commands,f)
    f.seek(0)
    commands2 = pickle.load(f)
    if commands == commands2:
        print('They are the same')
    else:
        print('They are different')

I have done alot of reading on python docs for pickles and file io but am unable to discern why there is a difference between my original object and the unpickled one

Upvotes: 0

Views: 420

Answers (1)

mata
mata

Reputation: 69042

After pickling and unpickling, obviously command and command2 will never be the same object.

That means commands == commands2 will always return False, unless you implement comparision for your class, for example:

class KeyCommand(Command):
    ...
    def __eq__(self, other):
        return self.data == other.data
    def __ne__(self, other):
        return self.data != other.data
    ...

class SystemCommand(Command):
    ...
    def __eq__(self, other):
        return self.data == other.data
    def __ne__(self, other):
        return self.data != other.data
    ...

Upvotes: 2

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