Crate ndarray_npy

This crate provides methods to read/write ndarray’s ArrayBase type from/to .npy and .npz files.

See the repository for information about the default features and how to use this crate with Cargo.

.npy Files

• Reading
  • ReadNpyExt extension trait
  • read_npy convenience function
• Writing
  • WriteNpyExt extension trait
  • write_npy convenience function
  • write_zeroed_npy to write an .npy file (sparse if possible) of zeroed data
• Readonly viewing (primarily for use with memory-mapped files)
  • ViewNpyExt extension trait
• Mutable viewing (primarily for use with memory-mapped files)
  • ViewMutNpyExt extension trait

It’s possible to create .npy files larger than the available memory with write_zeroed_npy and then modify them by memory-mapping and using ViewMutNpyExt.

.npz Files

• Reading: NpzReader
• Writing: NpzWriter

Limitations

• Parsing of .npy files is currently limited to files where the descr field of the header dictionary is a Python string literal of the form 'string', "string", '''string''', or """string""".

• The element traits (WritableElement, ReadableElement, ViewElement, and ViewMutElement) are currently implemented only for fixed-size integers up to 64 bits, floating point numbers, complex floating point numbers (if enabled with the crate feature), and bool.

The plan is to add support for more element types (including custom user-defined structs) in the future.

Structs

NpzReader

Reader for .npz files.

NpzWriter

Writer for .npz files.

Enums

ReadDataError

An error reading array data.

ReadNpyError

An error reading a .npy file.

ReadNpzError

An error reading a .npz file.

ViewDataError

An error viewing array data.

ViewNpyError

An error viewing a .npy file.

WriteDataError

An error writing array data.

WriteNpyError

An error writing a .npy file.

WriteNpzError

An error writing a .npz file.

Traits

ReadNpyExt

Extension trait for reading Array from .npy files.

ReadableElement

An array element type that can be read from an .npy or .npz file.

ViewElement

An array element type that can be viewed (without copying) in an .npy file.

ViewMutElement

An array element type that can be mutably viewed (without copying) in an .npy file.

ViewMutNpyExt

Extension trait for creating an ArrayViewMut from a mutable buffer containing an .npy file.

ViewNpyExt

Extension trait for creating an ArrayView from a buffer containing an .npy file.

WritableElement

An array element type that can be written to an .npy or .npz file.

WriteNpyExt

Extension trait for writing ArrayBase to .npy files.

Functions

read_npy

Read an .npy file located at the specified path.

write_npy

Writes an array to an .npy file at the specified path.

write_zeroed_npy

Writes an .npy file (sparse if possible) with bitwise-zero-filled data.