python2和python3之间的pandas.DataFrame.load/save:pickle协议问题

Question

我还没弄清楚如何使用pandas DataFrames在python 2和3之间进行pickle加载/保存.在选手中有一个'协议'选项,我玩过但没有成功,但我希望有人有一个快速的想法让我尝试.以下是获取错误的代码:

python2.7

>>> import pandas; from pylab import *
>>> a = pandas.DataFrame(randn(10,10))
>>> a.save('a2')
>>> a = pandas.DataFrame.load('a2')
>>> a = pandas.DataFrame.load('a3')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python2.7/site-packages/pandas-0.10.1-py2.7-linux-x86_64.egg/pandas/core/generic.py", line 30, in load
    return com.load(path)
  File "/usr/local/lib/python2.7/site-packages/pandas-0.10.1-py2.7-linux-x86_64.egg/pandas/core/common.py", line 1107, in load
    return pickle.load(f)
ValueError: unsupported pickle protocol: 3

python3

>>> import pandas; from pylab import *
>>> a = pandas.DataFrame(randn(10,10))
>>> a.save('a3')
>>> a = pandas.DataFrame.load('a3')
>>> a = pandas.DataFrame.load('a2')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.3/site-packages/pandas-0.10.1-py3.3-linux-x86_64.egg/pandas/core/generic.py", line 30, in load
    return com.load(path)
  File "/usr/local/lib/python3.3/site-packages/pandas-0.10.1-py3.3-linux-x86_64.egg/pandas/core/common.py", line 1107, in load
    return pickle.load(f)
UnicodeDecodeError: 'ascii' codec can't decode byte 0xf4 in position 0: ordinal not in range(128)

也许期待在python版本之间工作的泡菜有点乐观？

Answer 1

我有同样的问题.您可以使用python3中的以下函数更改dataframe pickle文件的协议:

import pickle
def change_pickle_protocol(filepath,protocol=2):
    with open(filepath,'rb') as f:
        obj = pickle.load(f)
    with open(filepath,'wb') as f:
        pickle.dump(obj,f,protocol=protocol)

那么你应该能够在python2中打开它没问题.