anndata - Annotated data

anndata is a Python package for handling annotated data matrices in memory and on disk, positioned between pandas and xarray. anndata offers a broad range of computationally efficient features including, among others, sparse data support, lazy operations, and a PyTorch interface.

• Discuss development on GitHub.

• Read the documentation.

• Ask questions on the scverse Discourse.

• Install via pip install anndata or conda install anndata -c conda-forge.

• Consider citing the anndata paper.

• See Scanpy’s documentation for usage related to single cell data. anndata was initially built for Scanpy.

News

Muon paper published 2022-02-02

Muon has been published in Genome Biology [^cite_bredikhin22]. Muon is a framework for multimodal data built on top of AnnData.

Check out Muon and its datastructure MuData.

COVID-19 datasets distributed as h5ad 2020-04-01

In a joint initiative, the Wellcome Sanger Institute, the Human Cell Atlas, and the CZI distribute datasets related to COVID-19 via anndata’s h5ad files: covid19cellatlas.org.

Latest additions

Version 0.9

0.9.0.rc1 2023-02-21

Features

• Added experimental support for dask arrays #813 @syelman @rahulbshrestha

• obsm, varm and uns can now hold AwkwardArrays #647 @giovp, @grst, @ivirshup

• Added experimental functions anndata.experimental.read_dispatched() and anndata.experimental.write_dispatched() which allow customizing IO with a callback #873 @ilan-gold @ivirshup

• Better error messages during IO #734 @flying-sheep, @ivirshup

• Unordered categorical columns are no longer cast to object during anndata.concat() #763 @ivirshup

Documentation

• New tutorials for experimental features

  • Dask Array Support to AnnData – #886 @syelman

  • Dask + Zarr, but Remote! – scverse/anndata-tutorials#17 @ilan-gold

  • Awkward Arrays in AnnData – scverse/anndata-tutorials#15 @grst

• File format description now includes a more formal specification #882 @ivirshup

• Interoperability: new page on interoperability with other packages #831 @ivirshup

• Expanded docstring more documentation for backed argument of anndata.read_h5ad() #812 @jeskowagner

• Documented how to use alternative compression methods for the h5ad file format, see AnnData.write_h5ad() #857 @nigeil

• General typo corrections 😅 #870 @folded

Breaking changes

• The AnnData dtype argument no longer defaults to float32 #854 @ivirshup

• Previously deprecated force_dense arugment AnnData.write_h5ad() has been removed. #855 @ivirshup

• Previously deprecated behaviour around storing adjacency matrices in uns has been removed #866 @ivirshup

Other updates

• Bump minimum python version to 3.8 #820 @ivirshup

Deprecations

• AnnData.concatenate() is now deprecated in favour of anndata.concat() #845 @ivirshup

Bug fixes

• Fixed order dependent outer concatenation bug #904 @ivirshup, reported by @szalata

• Fixed bug in renaming categories #790 @ivirshup, reported by @perrin-isir

• Fixed IO bug when keys in uns ended in _categories #806 @ivirshup, reported by @Hrovatin

• Fixed raw.to_adata not populating obs aligned values when raw was assigned through the setter #939 @ivirshup

Version 0.8

0.8.1 the future

Bug fixes

• Fix warning from rename_categories #790 I Virshup

• Remove backwards compat checks for categories in uns when we can tell the file is new enough #790 I Virshup

• Categorical arrays are now created with a python bool instead of a numpy.bool_ #856

Documentation

0.8.0 14th March, 2022

IO Specification

Warning

The on disk format of AnnData objects has been updated with this release. Previous releases of anndata will not be able to read all files written by this version.

For discussion of possible future solutions to this issue, see #698

Internal handling of IO has been overhauled. This should make it much easier to support new datatypes, use partial access, and use AnnData internally in other formats.

• Each element should be tagged with an encoding_type and encoding_version. See updated docs on the file format

• Support for nullable integer and boolean data arrays. More data types to come!

• Experimental support for low level access to the IO API via read_elem() and write_elem()

Features

• Added PyTorch dataloader AnnLoader and lazy concatenation object AnnCollection. See the tutorials #416 S Rybakov

• Compatibility with h5ad files written from Julia #569 I Kats

• Many logging messages that should have been warnings are now warnings #650 I Virshup

• Significantly more efficient anndata.read_umi_tools() #661 I Virshup

• Fixed deepcopy of a copy of a view retaining sparse matrix view mixin type #670 M Klein

• In many cases X can now be None #463 R Cannoodt #677 I Virshup. Remaining work is documented in #467.

• Removed hard xlrd dependency I Virshup

• obs and var dataframes are no longer copied by default on AnnData instantiation #371 I Virshup

Bug fixes

• Fixed issue where .copy was creating sparse matrices views when copying #670 michalk8

• Fixed issue where .X matrix read in from zarr would always have float32 values #701 I Virshup

• Raw.to_adata` now includes obsp in the output #404 G Eraslan

Dependencies

• xlrd dropped as a hard dependency

• Now requires h5py v3.0.0 or newer