Como instalar o Python 3 no macOS

Installing Python 3 isn’t the easiest thing to do on macOS. It’s not exceptionally hard but you need to know what conditions you’re working with. Hopefully, we can take most of the confusion out of the process. Here’s how you can install Python 3 on macOS.

Requirements

This is for macOS Catalina. macOS comes pre-installed with Python but on Catalina, this is version 2.7 which has reached the end of its life. This will create a few hiccups in the process but let’s start with the basics.

First, install Xcode on your Mac. You can get it from the Mac App Store. Once installed, make sure that the app is running. Launch it once to ensure there isn’t a problem.

Next, open Terminal and run the following command. This will install Command Line tools for Xcode. You need these to install Homebrew. The process is short and simple. You only need to follow the on-screen prompts.

xcode-select --install

Finally, run the following command in Terminal to install Homebrew

/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"

Install Python 3

Now that you’ve installed the basic apps you need, you can install Python 3. Open a new Terminal window, and run the following command.

brew install python3

The installation won’t take too long but you may need to authenticate with your user password during the installation process. Once it’s complete, you will see a message telling you that Python 3 was installed. Now you need to install pip.

pip is a package manager for Python. When you install Python scripts or apps, you often see ‘pip’ at the start of the install command. To install pip, run the following command in Terminal.

brew postinstall python3

This command may, or may not work. If you see the ‘setup.py –no-user-cfg install ‘ message in Terminal, this means that pip did not install. If that’s the case, simply run this command instead and it will install pip.

sudo easy_install pip

Python 2 vs Python 3

Python 2 is still on your system even though you’ve installed Python 3. In order to send commands to Python 3, you will need to enter python3 in the terminal. If you enter python, the command will be sent to Python 2.

Assuming you’ve now installed Python 3, you can check it by running the following command in Terminal.

python3 --version

Notice that we entered python3 and not just python. If you enter python –version, you will get a different version number i.e., the Python 2 version. At this point, we don’t recommend removing Python 2 from macOS since there are still a few kinks that Python 3 and pip have on the Mac platform. It is always a good idea to have the old version to fall back on.