将 numpy 数组输入和输出到 h5py

I have a Python code whose output is a sized matrix, whose entries are all of the type float. If I save it with the extension .dat the file size is of the order of 500 MB. I read that using h5py reduces the file size considerably. So, let's say I have the 2D numpy array named A. How do I save it to an h5py file? Also, how do I read the same file and put it as a numpy array in a different code, as I need to do manipulations with the array?

h5py提供了一个模型datasets and groups。前者基本上是数组，后者你可以将其视为目录。每个都有名字。您应该查看 API 的文档和示例：

http://docs.h5py.org/en/latest/quick.html http://docs.h5py.org/en/latest/quick.html

一个简单的示例，您预先创建所有数据并且只想将其保存到 hdf5 文件中，如下所示：

In [1]: import numpy as np
In [2]: import h5py
In [3]: a = np.random.random(size=(100,20))
In [4]: h5f = h5py.File('data.h5', 'w')
In [5]: h5f.create_dataset('dataset_1', data=a)
Out[5]: <HDF5 dataset "dataset_1": shape (100, 20), type "<f8">

In [6]: h5f.close()

然后您可以使用以下命令加载该数据： '

In [10]: h5f = h5py.File('data.h5','r')
In [11]: b = h5f['dataset_1'][:]
In [12]: h5f.close()

In [13]: np.allclose(a,b)
Out[13]: True

一定要查看文档：

http://docs.h5py.org http://docs.h5py.org

写入 hdf5 文件取决于 h5py 或 pytables（每个都有不同的 python API，位于 hdf5 文件规范之上）。您还应该看看 numpy 本身提供的其他简单二进制格式，例如np.save, np.savez etc:

http://docs.scipy.org/doc/numpy/reference/routines.io.html http://docs.scipy.org/doc/numpy/reference/routines.io.html