Input and output

NumPy binary files (NPY, NPZ)

load(file[, mmap_mode, allow_pickle, …])	Load arrays or pickled objects from .npy, .npz or pickled files.
save(file, arr[, allow_pickle, fix_imports])	Save an array to a binary file in NumPy .npy format.
savez(file, \*args, \*\*kwds)	Save several arrays into a single file in uncompressed .npz format.
savez_compressed(file, \*args, \*\*kwds)	Save several arrays into a single file in compressed .npz format.

The format of these binary file types is documented in numpy.lib.format

Text files

loadtxt(fname[, dtype, comments, delimiter, …])	Load data from a text file.
savetxt(fname, X[, fmt, delimiter, newline, …])	Save an array to a text file.
genfromtxt(fname[, dtype, comments, …])	Load data from a text file, with missing values handled as specified.
fromregex(file, regexp, dtype[, encoding])	Construct an array from a text file, using regular expression parsing.
fromstring(string[, dtype, count, sep])	A new 1-D array initialized from text data in a string.
ndarray.tofile(fid[, sep, format])	Write array to a file as text or binary (default).
ndarray.tolist()	Return the array as an a.ndim-levels deep nested list of Python scalars.

Raw binary files

fromfile(file[, dtype, count, sep, offset])	Construct an array from data in a text or binary file.
ndarray.tofile(fid[, sep, format])	Write array to a file as text or binary (default).

String formatting

array2string(a[, max_line_width, precision, …])	Return a string representation of an array.
array_repr(arr[, max_line_width, precision, …])	Return the string representation of an array.
array_str(a[, max_line_width, precision, …])	Return a string representation of the data in an array.
format_float_positional(x[, precision, …])	Format a floating-point scalar as a decimal string in positional notation.
format_float_scientific(x[, precision, …])	Format a floating-point scalar as a decimal string in scientific notation.

Memory mapping files

memmap

Create a memory-map to an array stored in a binary file on disk.

Text formatting options

set_printoptions([precision, threshold, …])	Set printing options.
get_printoptions()	Return the current print options.
set_string_function(f[, repr])	Set a Python function to be used when pretty printing arrays.
printoptions(\*args, \*\*kwargs)	Context manager for setting print options.

Base-n representations

binary_repr(num[, width])	Return the binary representation of the input number as a string.
base_repr(number[, base, padding])	Return a string representation of a number in the given base system.

Data sources

DataSource([destpath])

A generic data source file (file, http, ftp, …).

Binary Format Description

lib.format

Binary serialization