nlcpy.savez

nlcpy.savez(file, *args, **kwds)[source]

Saves several arrays into a single file in uncompressed .npz format.

If arguments are passed in with no keywords, the corresponding variable names, in the .npz file, are ‘arr_0’, ‘arr_1’, etc. If keyword arguments are given, the corresponding variable names, in the .npz file will match the keyword names.

Parameters

filestr or file: Either the file name (string) or an open file (file-like object) where the data will be saved. If file is a string or a Path, the .npz extension will be appended to the file name if it is not already there.
argsArguments, optional: Arrays to save to the file. Since it is not possible for Python to know the names of the arrays outside savez, the arrays will be saved with names “arr_0”, “arr_1”, and so on. These arguments can be any expression.
kwdskeyword arguments, optional: Arrays to save to the file. Arrays will be saved in the file with the keyword names.

See also

save: Saves an array to a binary file in NumPy .npy format.
savetxt: Saves an array to a text file.
savez_compressed: Saves several arrays into a single file in compressed .npz format.

Note

The .npz file format is a zipped archive of files named after the variables they contain. The archive is not compressed and each file in the archive contains one variable in .npy format. For a description of the .npy format, see numpy.lib.format.

When opening the saved .npz file with load() a NpzFile object is returned. This is a dictionary-like object which can be queried for its list of arrays (with the .files attribute), and for the arrays themselves.

Examples

>>> import nlcpy as vp
>>> from tempfile import TemporaryFile
>>> outfile = TemporaryFile()
>>> x = vp.arange(10)
>>> y = vp.sin(x)

Using savez with *args, the arrays are saved with default names.

>>> vp.savez(outfile, x, y)
>>> _ = outfile.seek(0) # Only needed here to simulate closing & reopening file
>>> npzfile = vp.load(outfile)
>>> npzfile.files
['arr_0', 'arr_1']
>>> npzfile['arr_0']
array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])

Using savez with **kwds, the arrays are saved with the keyword names.

>>> outfile = TemporaryFile()
>>> vp.savez(outfile, x=x, y=y)
>>> _ = outfile.seek(0)
>>> npzfile = vp.load(outfile)
>>> sorted(npzfile.files)
['x', 'y']
>>> npzfile['x']
array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])