The file object created by open() does not support the seekable() function in python 2.7 (but it does in python 3), which will lead to an AttributeError: 'file' object has no attribute 'seekable' error on the following calls:

https://github.com/joblib/joblib/blob/master/joblib/numpy_pickle_utils.py#L351
https://github.com/joblib/joblib/blob/master/joblib/numpy_pickle_utils.py#L389

A possible solution would be to replace open with io.open, but that wouldn't help if the user passed in a file object.