Upgrading from Python2 to Python3 on MacOS
Like most developers using MacOS, we use Homebrew to install and update software/casks. As of this writing, I was having challenges updating Python2 to Python3. Here’s how I fixed it.
Steps Taken
1 Check Version
Run: $ brew info python
Result:
python: stable 3.7.7 (bottled), HEAD
Interpreted, interactive, object-oriented programming language
https://www.python.org/
Not installed
From: https://github.com/Homebrew/homebrew-core/blob/master/Formula/python.rb
==> Dependencies
Build: pkg-config ✘
Required: gdbm ✔, openssl@1.1 ✔, readline ✔, sqlite ✔, xz ✔
==> Options
--HEAD
Install HEAD version
==> Caveats
Python has been installed as
/usr/local/bin/python3
Unversioned symlinks `python`, `python-config`, `pip` etc. pointing to`python3`, `python3-config`, `pip3` etc., respectively, have been installed into
/usr/local/opt/python/libexec/bin
You can install Python packages with
pip3 install <package>
They will install into the site-package directory
/usr/local/lib/python3.7/site-packages
See: https://docs.brew.sh/Homebrew-and-Python
==> Analytics
install: 198,504 (30 days), 1,021,773 (90 days), 5,245,160 (365 days)
install-on-request: 162,871 (30 days), 639,716 (90 days), 2,755,324 (365 days)
build-error: 0 (30 days)2 Installation through Homebrew
Ran $ brew install python
There were some errors produced after:
Error: The `brew link` step did not complete successfully
The formula built, but is not symlinked into /usr/local
Could not symlink bin/2to3
Target /usr/local/bin/2to3
already exists. You may want to remove it:
rm '/usr/local/bin/2to3'
To force the link and overwrite all conflicting files:
brew link --overwrite python
To list all files that would be deleted:
brew link --overwrite --dry-run python
Possible conflicting files are:
/usr/local/bin/2to3 -> /Library/Frameworks/Python.framework/Versions/3.8/bin/2to3
/usr/local/bin/idle3 -> /Library/Frameworks/Python.framework/Versions/3.8/bin/idle3
/usr/local/bin/pydoc3 -> /Library/Frameworks/Python.framework/Versions/3.8/bin/pydoc3
/usr/local/bin/python3 -> /Library/Frameworks/Python.framework/Versions/3.8/bin/python3
/usr/local/bin/python3-config -> /Library/Frameworks/Python.framework/Versions/3.8/bin/python3-config
Error: Permission denied @ dir_s_mkdir - /usr/local/FrameworksI tried removing the folder one by one and forgot you can just override it. Don’t worry, it’s safe. (^^,)
Execute with this command: $ brew link --overwrite python
Another one! -DJ Khaled
The error:
Linking /usr/local/Cellular/python/3.7.7... Error: Permission Denied @ dir_s_mkdir — /usr/local/Frameworks
Google is our Friend (privacy not included)
Turns out it’s an existing issue. Remember, Homebrew doesn’t allow or recommend to execute brew commands with sudo anymore to prevent issues.
Source: https://github.com/Homebrew/homebrew-core/issues/30652
So we executed the following commands:
$ sudo mkdir /usr/local/Frameworks
$ sudo chown $USER /usr/local/Frameworks
Then: $ brew link python
Final result?
Linking /usr/local/Cellular/python/3.7.7... 5 symlinks created