问题
Is there any way to remove a dataset from an hdf5 file, preferably using h5py? Or alternatively, is it possible to overwrite a dataset while keeping the other datasets intact?
To my understanding, h5py can read/write hdf5 files in 5 modes
f = h5py.File("filename.hdf5",'mode')
where mode can be rfor read, r+ for read-write, a for read-write but creates a new file if it doesn't exist, w for write/overwrite, and w- which is same as w but fails if file already exists. I have tried all but none seem to work.
Any suggestions are much appreciated.
回答1:
Yes, this can be done.
with h5py.File(input, "a") as f:
del f[datasetname]
You will need to have the file open in a writeable mode, for example append (as above) or write.
As noted by @seppo-enarvi in the comments the purpose of the previously recommended f.__delitem__(datasetname) function is to implement the del operator, so that one can delete a dataset using del f[datasetname]
回答2:
I do not understand what has your question to do with the file open modes. For read/write r+ is the way to go.
To my knowledge, removing is not easy/possible, in particular no matter what you do the file size will not shrink.
But overwriting content is no problem
f['mydataset'][:] = 0
回答3:
I tried this out and the only way I could actually reduce the size of the file is by copying everything to a new file and just leaving out the dataset I was not interested in:
fs = h5py.File('WFA.h5', 'r')
fd = h5py.File('WFA_red.h5', 'w')
for a in fs.attrs:
fd.attrs[a] = fs.attrs[a]
for d in fs:
if not 'SFS_TRANSITION' in d: fs.copy(d, fd)
来源：https://stackoverflow.com/questions/31861724/deleting-hdf5-dataset-using-h5py