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Diffstat (limited to 'numpy/lib/format.py')
| -rw-r--r-- | numpy/lib/format.py | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/numpy/lib/format.py b/numpy/lib/format.py index 67da0d6d1..4ff0a660f 100644 --- a/numpy/lib/format.py +++ b/numpy/lib/format.py @@ -128,6 +128,19 @@ Consumers can figure out the number of bytes by multiplying the number of elements given by the shape (noting that ``shape=()`` means there is 1 element) by ``dtype.itemsize``. +Format Version 2.0 +------------------ + +The version 1.0 format only allowed the array header to have a total size of +65535 bytes. This can be exceeded by structured arrays with a large number of +columns. The version 2.0 format extends the header size to 4 GiB. +`numpy.save` will automatically save in 2.0 format if the data requires it, +else it will always use the more compatible 1.0 format. + +The description of the fourth element of the header therefore has become: +"The next 4 bytes form a little-endian unsigned int: the length of the header +data HEADER_LEN." + Notes ----- The ``.npy`` format, including reasons for creating it and a comparison of |