How do you save/load a scipy sparse `csr_matrix` in a portable format? The scipy sparse matrix is created on Python 3 (Windows 64-bit) to run on Python 2 (Linux 64-bit). Initially, I used pickle (with protocol=2 and fix\_imports=True) but this didn't work going from Python 3.2.2 (Windows 64-bit) to Python 2.7.2 (Windows 32-bit) and got the error:

```
TypeError: ('data type not understood', <built-in function _reconstruct>, (<type 'numpy.ndarray'>, (0,), '[98]')).

```

Next, tried `numpy.save` and `numpy.load` as well as `scipy.io.mmwrite()` and `scipy.io.mmread()` and none of these methods worked either.