I am trying to get to grips with Python on my Mac running OSX 10.15.7 Catalina.
My goal is to be able to run a program requiring python 3.9 and associated libraries, in its own virtual environment, using venv.
My quest has led me over many rocky paths and blind alleys - including via Anaconda and Brew.
I am running zsh - specifically oh-my-zsh ys version. If that’s important. Most online forums and tutorials assume bash. I would prefer to do all in zsh to avoid having to edit both zsh and bash profiles.
Current Shell Outputs
$ python -V
Python 2.7.16
$ which python
/usr/bin/python
$ python3 -V
Python 3.8.2
$ which python3.8
python3.8 not found
$ which python3.9
python3.9 not found
$ python3 -m -V
/Library/Developer/CommandLineTools/usr/bin/python3: No module named -V
Pausing there ..
Py 2.7 is the OSX system python and I don’t want to do anything with it.
It is odd that python3 -m returns a reference to the CLI tools. See below. The only location for py3.8 is in the CL tools.
What pythons do I have (output below is edited so as to show only main directories and files)?
$ locate python
/Applications/LibreOffice.app/Contents/Frameworks/LibreOfficePython.framework/Versions/3.7/bin/python3
/Library/Developer/CommandLineTools/Library/Frameworks/Python3.framework/Versions/3.8/bin/python3.8
/Library/Developer/CommandLineTools/SDKs/MacOSX10.15.sdk/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/python
/Library/Developer/CommandLineTools/usr/bin/python3.8
/Library/Frameworks/Python.framework/Versions/3.9/bin/python3
/Library/Frameworks/Python.framework/Versions/3.9/bin/python3-config
/Library/Frameworks/Python.framework/Versions/3.9/bin/python3.9
/Library/Frameworks/Python.framework/Versions/3.9/bin/python3.9-config
/Library/Frameworks/Python.framework/Versions/3.9/share/man/man1/python3.1
/Library/Frameworks/Python.framework/Versions/3.9/share/man/man1/python3.9.1
/Library/Frameworks/SAVI.framework/Versions/A/Frameworks/Python.framework/Versions/3.6/lib/python3.6
/usr/bin/python
/usr/bin/python-config
/usr/bin/python2
/usr/bin/python2.7
/usr/bin/python2.7-config
/usr/bin/python3
/usr/bin/pythonw
/usr/bin/pythonw2.7
/usr/lib/libpython.dylib
/usr/lib/libpython2.7.dylib
/usr/lib/python2.7
/usr/local/bin/python3
/usr/local/bin/python3-config
/usr/local/bin/python3.9
/usr/local/bin/python3.9-config
/usr/share/file/magic/python
/usr/share/man/man1/python.1
/usr/share/man/man1/python2.7.1
/usr/share/man/man1/pythonw.1
/usr/share/man/man1/pythonw2.7.1
/usr/share/vim/vim81/autoload/python3complete.vim
/usr/share/vim/vim81/autoload/pythoncomplete.vim
/usr/share/vim/vim81/ftplugin/python.vim
/usr/share/vim/vim81/indent/python.vim
/usr/share/vim/vim81/syntax/python.vim
/usr/share/zsh/5.7.1/functions/_bpython
/usr/share/zsh/5.7.1/functions/_python
/usr/share/zsh/5.7.1/functions/_python_modules
WHAT ABOUT PIP?
$ pip3
WARNING: pip is being invoked by an old script wrapper. This will fail in a future version of pip.
Please see https://github.com/pypa/pip/issues/5599 for advice on fixing the underlying issue.
To avoid this problem you can invoke Python with '-m pip' instead of running pip directly.
$ pip3 install --upgrade pip
WARNING: pip is being invoked by an old script wrapper. This will fail in a future version of pip.
Please see https://github.com/pypa/pip/issues/5599 for advice on fixing the underlying issue.
To avoid this problem you can invoke Python with '-m pip' instead of running pip directly.
Defaulting to user installation because normal site-packages is not writeable
Requirement already satisfied: pip in ./Library/Python/3.8/lib/python/site-packages (20.3.3)
Note two points
1 Although the wrapper warning comes up, PIP 20.3.3 is latest version which I have upgraded. Probably the reason for the warning is in the next lines, which suggest that PIP3 is being invoked from the CL Tools.
2 The ‘Normal site packages not writable’ error is supposed to be cured by specifying the Path. I have tried already to specify the correct path - see below - but this has not cured the problem and is another major reason for asking the question at the end of this post.
$ python -m pip
/System/Library/Frameworks/Python.framework/Versions/2.7/Resources/Python.app/Contents/MacOS/Python: No module named pip
$ python3 -m pip
Usage:
/Library/Developer/CommandLineTools/usr/bin/python3 -m pip <command> [options]
$ which pip3
/usr/bin/pip3
$ locate pip3
/Applications/LibreOffice.app/Contents/Frameworks/LibreOfficePython.framework/Versions/3.7/bin/pip3
/Applications/LibreOffice.app/Contents/Frameworks/LibreOfficePython.framework/Versions/3.7/bin/pip3.7
/Library/Developer/CommandLineTools/usr/bin/pip3
/Library/Developer/CommandLineTools/usr/bin/pip3.8
/Library/Frameworks/Python.framework/Versions/3.9/bin/pip3
/Library/Frameworks/Python.framework/Versions/3.9/bin/pip3.9
/usr/bin/pip3
/usr/local/bin/pip3
/usr/local/bin/pip3.9
SYSTEM FILES
~/.zprofile contents - edited a few times to remove references to virfualenv and penv, both originally installed with brew and now removed. I have run brew uninstall and brew remove to try to clean everything up but may not have succeeded.
Start
# THIS FILE COMMENTED OUT RH 21DEC20
## Setting PATH for Python 3.9
## The original version is saved in .zprofile.pysave. **Note in this post only - cannot find this file**
PATH="/Library/Frameworks/Python.framework/Versions/3.9/bin:${PATH}"
export PATH **Note in this post only - this does not seem to have worked - see above Python3 -V**
# export WORKON_HOME=~/.virtualenvs
# mkdir -p $WORKON_HOME
# . ~/.pyenv/versions/3.9.0/bin/virtualenvwrapper.sh
# eval "$(pyenv init -)"
# # AND THESE LINES ADDED FOLLOWING STACKOVERFLOW Q 33216679 **Note in this post only - commented out as shell threw errors .’cannot find virtualenvwrapper.sh**
# export WORKON_HOME=$HOME/.Envs
# # export VIRTUALENVWRAPPER_PYTHON=$/usr/bin/python3
# export VIRTUALENVWRAPPER_PYTHON=$/usr/local/bin/python3
#source $HOME/.local/bin/virtualenvwrapper.sh
END
Finally a word about Brew. Many tutorials advised the use of Brew to install Python, pyenv and libraries etc. I did that and successfully created a test environment, but could not the utilise it. I have then removed as much as possible in order to get back to a ‘clean’ state to work with.
Current brew status is
$ brew doctor
Please note that these warnings are just used to help the Homebrew maintainers
with debugging if you file an issue. If everything you use Homebrew for is
working fine: please don't worry or file an issue; just ignore this. Thanks!
Warning: Unbrewed dylibs were found in /usr/local/lib.
If you didn't put them there on purpose they could cause problems when
building Homebrew formulae, and may need to be deleted.
Unexpected dylibs:
/usr/local/lib/libdvdcss.2.dylib
/usr/local/lib/libfuse.0.dylib
/usr/local/lib/libulockmgr.0.dylib
Warning: Unbrewed header files were found in /usr/local/include.
If you didn't put them there on purpose they could cause problems when
building Homebrew formulae, and may need to be deleted.
Unexpected header files:
/usr/local/include/ulockmgr.h
Warning: Unbrewed .la files were found in /usr/local/lib.
If you didn't put them there on purpose they could cause problems when
building Homebrew formulae, and may need to be deleted.
Unexpected .la files:
/usr/local/lib/libulockmgr.la
Warning: Unbrewed static libraries were found in /usr/local/lib.
If you didn't put them there on purpose they could cause problems when
building Homebrew formulae, and may need to be deleted.
Unexpected static libraries:
/usr/local/lib/libfuse.a
/usr/local/lib/libulockmgr.a
SUMMARY
My first goal is to set Py3.9.x as default for new projects. I think also this would require/imply that pip and other commands run from v3.9 and not any other version or location. Must admit to being hazy about that.
Then I want to be able to create a virtual environment into which I can put the program I want to run and its associated libraries and packages. Doing this implies using terminal, but I need to know which directory I need to be in to run which commands.
At this point I have also been running into confusion with tutorials on how to create a virtual environment. From what I have read I think I should use venv over pyenv. What is not clear is whether I run the venv command(s) from root, or whether I have to create and cd to a different location, and if so what.
Any help in
1 Changing the default python to 3.9
2 Creating a venv to use v3.9.
3 What commands to run where.
Will be greatly appreciated. Please keep it simple and don’t assume any prior knowledge!
Best and Happy Christmas to all.