python 3.x - unable to install matplotlib with python3 on m1 mac using pip3

Question

I'm unable to install matplotlib through pip on my M1 Mac. I have Python 3.9.1 installed through Homebrew. I've tried the solution here: Pip install matplotlib fails on M1 Mac but it does not work for me.

I get this long error:

ImportError: dlopen(/opt/homebrew/lib/python3.9/site-packages/numpy/core/_multiarray_umath.cpython-39-darwin.so, 2): no suitable image found.  Did find:
    /opt/homebrew/lib/python3.9/site-packages/numpy/core/_multiarray_umath.cpython-39-darwin.so: mach-o, but wrong architecture
    /opt/homebrew/lib/python3.9/site-packages/numpy/core/_multiarray_umath.cpython-39-darwin.so: mach-o, but wrong architecture

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/private/tmp/pip-install-mrz7uc56/matplotlib_20151701613b4e6fb6955488fa89e81e/setup.py", line 256, in <module>
    setup(  # Finally, pass this all along to distutils to do the heavy lifting.
  File "/opt/homebrew/lib/python3.9/site-packages/setuptools/__init__.py", line 153, in setup
    return distutils.core.setup(**attrs)
  File "/opt/homebrew/Cellar/python@3.9/3.9.1_8/Frameworks/Python.framework/Versions/3.9/lib/python3.9/distutils/core.py", line 148, in setup
    dist.run_commands()
  File "/opt/homebrew/Cellar/python@3.9/3.9.1_8/Frameworks/Python.framework/Versions/3.9/lib/python3.9/distutils/dist.py", line 966, in run_commands
    self.run_command(cmd)
  File "/opt/homebrew/Cellar/python@3.9/3.9.1_8/Frameworks/Python.framework/Versions/3.9/lib/python3.9/distutils/dist.py", line 985, in run_command
    cmd_obj.run()
  File "/opt/homebrew/lib/python3.9/site-packages/setuptools/command/egg_info.py", line 299, in run
    self.find_sources()
  File "/opt/homebrew/lib/python3.9/site-packages/setuptools/command/egg_info.py", line 306, in find_sources
    mm.run()
  File "/opt/homebrew/lib/python3.9/site-packages/setuptools/command/egg_info.py", line 541, in run
    self.add_defaults()
  File "/opt/homebrew/lib/python3.9/site-packages/setuptools/command/egg_info.py", line 577, in add_defaults
    sdist.add_defaults(self)
  File "/opt/homebrew/Cellar/python@3.9/3.9.1_8/Frameworks/Python.framework/Versions/3.9/lib/python3.9/distutils/command/sdist.py", line 228, in add_defaults
    self._add_defaults_ext()
  File "/opt/homebrew/Cellar/python@3.9/3.9.1_8/Frameworks/Python.framework/Versions/3.9/lib/python3.9/distutils/command/sdist.py", line 311, in _add_defaults_ext
    build_ext = self.get_finalized_command('build_ext')
  File "/opt/homebrew/Cellar/python@3.9/3.9.1_8/Frameworks/Python.framework/Versions/3.9/lib/python3.9/distutils/cmd.py", line 299, in get_finalized_command
    cmd_obj.ensure_finalized()
  File "/opt/homebrew/Cellar/python@3.9/3.9.1_8/Frameworks/Python.framework/Versions/3.9/lib/python3.9/distutils/cmd.py", line 107, in ensure_finalized
    self.finalize_options()
  File "/private/tmp/pip-install-mrz7uc56/matplotlib_20151701613b4e6fb6955488fa89e81e/setup.py", line 88, in finalize_options
    self.distribution.ext_modules[:] = [
  File "/private/tmp/pip-install-mrz7uc56/matplotlib_20151701613b4e6fb6955488fa89e81e/setup.py", line 91, in <listcomp>
    for ext in package.get_extensions()
  File "/private/tmp/pip-install-mrz7uc56/matplotlib_20151701613b4e6fb6955488fa89e81e/setupext.py", line 345, in get_extensions
    add_numpy_flags(ext)
  File "/private/tmp/pip-install-mrz7uc56/matplotlib_20151701613b4e6fb6955488fa89e81e/setupext.py", line 468, in add_numpy_flags
    import numpy as np
  File "/opt/homebrew/lib/python3.9/site-packages/numpy/__init__.py", line 145, in <module>
    from . import core
  File "/opt/homebrew/lib/python3.9/site-packages/numpy/core/__init__.py", line 48, in <module>
    raise ImportError(msg)
ImportError:

IMPORTANT: PLEASE READ THIS FOR ADVICE ON HOW TO SOLVE THIS ISSUE!

Importing the numpy C-extensions failed. This error can happen for
many reasons, often due to issues with your setup or how NumPy was
installed.

I am able to import matplotlib with python 2.7 on my Rosetta Terminal but I am trying to use matplotlib with python3 instead.

Any help would be appreciated!

Answer 1

In order to install matplotlib with pip3 on an M1 mac, you first need to install the dependencies Cython, numpy and Pillow from source. The following method worked for me.

0. Install Cython

pip3 install Cython

1. Install numpy

$ git clone https://github.com/numpy/numpy.git
$ cd numpy
$ pip3 install . --no-binary :all: --no-use-pep517

2. Install Pillow

libjpeg is necessary for Pillow so you might want to install it via brew.

$ brew install libjpeg
$ git clone https://github.com/python-pillow/Pillow.git
$ cd Pillow
$ pip3 install . --no-binary :all: --no-use-pep517

3. Install matplotlib

$ git clone https://github.com/matplotlib/matplotlib.git

Then you need to manually download qhull and extract the archive. (http://www.qhull.org/download/qhull-2020-src-8.0.2.tgz on Qhull Downloads) You will get a folder named qhull-2020.2. You then have to place the folder at matplotlib/build. The build folder may not exist so you might have to create it.

Lastly, the following command will install the matplotlib on your M1 mac.

$ cd matplotlib
$ pip3 install . --no-binary :all:

Tested for Python 3.9.1 on non-Rosetta terminal on M1 Mac mini (Big Sur 11.2.1).