【numpy】np.genfromtxt非常的慢，并且需要读取文件的10倍内存

issue 连接

​​https://github.com/numpy/numpy/issues/3477​​

今天使用np.genfromtxt加载一个5G不到的csv文件，把我30G内存+10Gswap都干满了还是报了out of memory.

一开始以为是open方法慢呢，原来是np.genfromtxt

一定要注意！！！！

np.genfromtxt非常的慢，并且需要读取文件的10倍内存

有问题的代码实例

with open(bin_file, 'r') as f:
    #读取5G的文件居然需要10倍大小的内存!!!!!
    csv = np.genfromtxt(f, delimiter=",", dtype='float32')
    csv = csv.reshape((count, shape_x, shape_y, shape_c))
    print(csv.shape)
    for i in range(count):
        dset[i,:,:,:] = csv[i, :,:,:]

替换方案

使用np.loadtxt

def write_h5(file):
    print("load file ", file)
    #csv = np.genfromtxt(f, delimiter=",", dtype='float32')
    csv = np.loadtxt(file, delimiter=',')
    print("load completed! ")

    csv = csv.reshape((total_count, shape_x, shape_y, shape_c))

    h5f = h5py.File(file_name, 'w')
    print("create h5file ", file_name)
    h5f.create_dataset(name='data',  data=csv)
    print("create h5file dataset")
    h5f.close()