不能鹹菜instancemethod對象

Question

我遇到了泡菜的問題，代碼是：

import cPickle 

class A(object): 

    def __init__(self): 
     self.a = 1 

    def methoda(self): 
     print(self.a) 


class B(object): 

    def __init__(self): 
     self.b = 2 
     a = A() 
     self.b_a = a.methoda 

    def methodb(self): 
     print(self.b) 
if __name__ == '__main__': 
    b = B() 
    with open('best_model1.pkl', 'w') as f: 
     cPickle.dump(b, f) 

錯誤是：

File "/usr/lib/python2.7/copy_reg.py", line 70, in _reduce_ex raise TypeError, "can't pickle %s objects" % base.name TypeError: can't pickle instancemethod objects

Answer 1

你可以，如果你使用dill代替cPickle。

>>> import dill  
>>> 
>>> class A(object): 
... def __init__(self): 
...  self.a = 1 
... def methods(self): 
...  print(self.a) 
... 
>>> 
>>> class B(object): 
... def __init__(self): 
...  self.b = 2 
...  a = A() 
...  self.b_a = a.methods 
... def methodb(self): 
...  print(self.b) 
... 
>>> b = B() 
>>> b_ = dill.dumps(b) 
>>> _b = dill.loads(b_) 
>>> _b.methodb() 
2 
>>> 

另見： Can't pickle <type 'instancemethod'> when using python's multiprocessing Pool.map()