NumPy 1.21.1 Release Notes#

The NumPy 1.21.1 is maintenance release that fixes bugs discovered after the 1.21.0 release and updates OpenBLAS to v0.3.17 to deal with problems on arm64.

The Python versions supported for this release are 3.7-3.9. The 1.21.x series is compatible with development Python 3.10. Python 3.10 will be officially supported after it is released.


There are unresolved problems compiling NumPy 1.20.0 with gcc-11.1.

  • Optimization level -O3 results in many incorrect warnings when running the tests.

  • On some hardware NumPY will hang in an infinite loop.


A total of 11 people contributed to this release. People with a “+” by their names contributed a patch for the first time.

  • Bas van Beek

  • Charles Harris

  • Ganesh Kathiresan

  • Gregory R. Lee

  • Hugo Defois +

  • Kevin Sheppard

  • Matti Picus

  • Ralf Gommers

  • Sayed Adel

  • Sebastian Berg

  • Thomas J. Fan

Pull requests merged#

A total of 26 pull requests were merged for this release.

  • #19311: REV,BUG: Replace NotImplemented with typing.Any

  • #19324: MAINT: Fixed the return-dtype of ndarray.real and imag

  • #19330: MAINT: Replace "dtype[Any]" with dtype in the definiton of…

  • #19342: DOC: Fix some docstrings that crash pdf generation.

  • #19343: MAINT: bump scipy-mathjax

  • #19347: BUG: Fix arr.flat.index for large arrays and big-endian machines

  • #19348: ENH: add numpy.f2py.get_include function

  • #19349: BUG: Fix reference count leak in ufunc dtype handling

  • #19350: MAINT: Annotate missing attributes of np.number subclasses

  • #19351: BUG: Fix cast safety and comparisons for zero sized voids

  • #19352: BUG: Correct Cython declaration in random

  • #19353: BUG: protect against accessing base attribute of a NULL subarray

  • #19365: BUG, SIMD: Fix detecting AVX512 features on Darwin

  • #19366: MAINT: remove print()’s in distutils template handling

  • #19390: ENH: SIMD architectures to show_config

  • #19391: BUG: Do not raise deprecation warning for all nans in unique…

  • #19392: BUG: Fix NULL special case in object-to-any cast code

  • #19430: MAINT: Use arm64-graviton2 for testing on travis

  • #19495: BUILD: update OpenBLAS to v0.3.17

  • #19496: MAINT: Avoid unicode characters in division SIMD code comments

  • #19499: BUG, SIMD: Fix infinite loop during count non-zero on GCC-11

  • #19500: BUG: fix a numpy.npiter leak in npyiter_multi_index_set

  • #19501: TST: Fix a GenericAlias test failure for python 3.9.0

  • #19502: MAINT: Start testing with Python 3.10.0b3.

  • #19503: MAINT: Add missing dtype overloads for object- and ctypes-based…

  • #19510: REL: Prepare for NumPy 1.21.1 release.