python3 -m pip install cython   
python3 -m pip install --no-binary :all: --no-use-pep517 numpy
brew install libjpeg
python3 -m pip install matplotlib

为我工作，此时它安装了numpy 1.20.1.

Worked for me, at this time it installed numpy 1.20.1.

来自 Homebrew 的相同 Python 版本 (3.9.1).

Same Python version (3.9.1) from Homebrew.