将新数据添加到HDF5文件会导致空数组

Question

在使用Python的HDF5包时，我发现了一个奇怪的行为。我想在表中插入更多数据。但不知怎的，我不能让它正常工作。正如您从源代码中看到的，我使用fromRow = hf["X"].shape[0]获取键“X”中的最后一行数据，然后写入tempArray2。结果是一个空表

import h5py

tempArray1 = [[0.9293237924575806, -0.32789671421051025, 0.18110771477222443], [0.9293237924575806, -0.32789671421051025, 0.18110771477222443], [0.9293237924575806, -0.32789671421051025, 0.18110771477222443], [0.9293237924575806, -0.32789671421051025, 0.18110771477222443], [0.9293237924575806, -0.32789671421051025, 0.18110771477222443], [0.9293237924575806, -0.32789671421051025, 0.18110771477222443], [0.9293237924575806, -0.32789671421051025, 0.18110771477222443], [0.9293237924575806, -0.32789671421051025, 0.18110771477222443], [0.9293237924575806, -0.32789671421051025, 0.18110771477222443], [0.9293237924575806, -0.32789671421051025, 0.18110771477222443]]
tempArray2 = [[3.1387749004352372e-06, 8.120089097236803e+27, -1.645612730013634e-14], [3.1387749004352372e-06, 8.120089097236803e+27, -1.645612730013634e-14], [3.1387749004352372e-06, 8.120089097236803e+27, -1.645612730013634e-14], [3.1387749004352372e-06, 8.120089097236803e+27, -1.645612730013634e-14], [3.1387749004352372e-06, 8.120089097236803e+27, -1.645612730013634e-14], [3.1387749004352372e-06, 8.120089097236803e+27, -1.645612730013634e-14], [3.1387749004352372e-06, 8.120089097236803e+27, -1.645612730013634e-14], [3.1387749004352372e-06, 8.120089097236803e+27, -1.645612730013634e-14], [3.1387749004352372e-06, 8.120089097236803e+27, -1.645612730013634e-14], [3.1387749004352372e-06, 8.120089097236803e+27, -1.645612730013634e-14]]

with h5py.File('data.hdf5', 'w') as hf:
    # Add data to new file
    dset = hf.create_dataset("X", data=tempArray1, compression="gzip", chunks=True, maxshape=(None,3), dtype='f4') # Size is as the size of tempArray1
    print(hf["X"].shape[0])

    # Append data existing file
    hf["X"].resize((hf["X"].shape[0] + 10, 3)) # Size is as the size of X+ 10
    print(hf["X"].shape[0])
    fromRow = hf["X"].shape[0]
    hf["X"][fromRow:] = tempArray2

这就是它的样子：

Key: X
Data:
 [[ 0.9293238  -0.3278967   0.18110771]
 [ 0.9293238  -0.3278967   0.18110771]
 [ 0.9293238  -0.3278967   0.18110771]
 [ 0.9293238  -0.3278967   0.18110771]
 [ 0.9293238  -0.3278967   0.18110771]
 [ 0.9293238  -0.3278967   0.18110771]
 [ 0.9293238  -0.3278967   0.18110771]
 [ 0.9293238  -0.3278967   0.18110771]
 [ 0.9293238  -0.3278967   0.18110771]
 [ 0.9293238  -0.3278967   0.18110771]
 [ 0.          0.          0.        ]
 [ 0.          0.          0.        ]
 [ 0.          0.          0.        ]
 [ 0.          0.          0.        ]
 [ 0.          0.          0.        ]
 [ 0.          0.          0.        ]
 [ 0.          0.          0.        ]
 [ 0.          0.          0.        ]
 [ 0.          0.          0.        ]
 [ 0.          0.          0.        ]]
Length of data: 20

奇怪的是，当我将值fromRow替换为数字10，比如fromRow = 10，表示现有表的结尾时，它就工作了

输出：

Key: X
Data:
 [[ 9.2932379e-01 -3.2789671e-01  1.8110771e-01]
 [ 9.2932379e-01 -3.2789671e-01  1.8110771e-01]
 [ 9.2932379e-01 -3.2789671e-01  1.8110771e-01]
 [ 9.2932379e-01 -3.2789671e-01  1.8110771e-01]
 [ 9.2932379e-01 -3.2789671e-01  1.8110771e-01]
 [ 9.2932379e-01 -3.2789671e-01  1.8110771e-01]
 [ 9.2932379e-01 -3.2789671e-01  1.8110771e-01]
 [ 9.2932379e-01 -3.2789671e-01  1.8110771e-01]
 [ 9.2932379e-01 -3.2789671e-01  1.8110771e-01]
 [ 9.2932379e-01 -3.2789671e-01  1.8110771e-01]
 [ 3.1387749e-06  8.1200891e+27 -1.6456127e-14]
 [ 3.1387749e-06  8.1200891e+27 -1.6456127e-14]
 [ 3.1387749e-06  8.1200891e+27 -1.6456127e-14]
 [ 3.1387749e-06  8.1200891e+27 -1.6456127e-14]
 [ 3.1387749e-06  8.1200891e+27 -1.6456127e-14]
 [ 3.1387749e-06  8.1200891e+27 -1.6456127e-14]
 [ 3.1387749e-06  8.1200891e+27 -1.6456127e-14]
 [ 3.1387749e-06  8.1200891e+27 -1.6456127e-14]
 [ 3.1387749e-06  8.1200891e+27 -1.6456127e-14]
 [ 3.1387749e-06  8.1200891e+27 -1.6456127e-14]]
Length of data: 20

知道我做错了什么吗

Answer 1

调整X数据集的大小后，您将得到fromRow。在调整大小之前，您需要该值。请参阅下面的代码

with h5py.File('data.hdf5', 'w') as hf:
    # Add data to new file
    dset = hf.create_dataset("X", data=tempArray1, compression="gzip", chunks=True, maxshape=(None,3), dtype='f4') # Size is as the size of tempArray1
    print(hf["X"].shape[0])
# new location to get fromRow:
    fromRow = hf["X"].shape[0]

    # Append data existing file
    hf["X"].resize((hf["X"].shape[0] + 10, 3)) # Size is as the size of X+ 10
    print(hf["X"].shape[0])        
    hf["X"][fromRow:] = tempArray2