# Installing Python3 on a Mac

Getting a sane Python3 runtime on a Mac can be tedious.  The most painless way I have found thus far installing a Python3 package from python.org and, from there, installing two additional packages into the system directory: `pip` and `pipx`.


# Install Python

Install Python with a package from python.org.  This post uses 3.6.8: https://www.python.org/downloads/release/python-368/

At this point, close the current shell and launch a new shell.  This will ensure you have Python 3.6 in your `PATH`; you should see something similar to:

```
$ which python3.6
/Library/Frameworks/Python.framework/Versions/3.6/bin/python3.6
```


# Installing pip

`pip` is the easiest, modern way to install 3rd party Python packages on your system.  It can be installed with the command:

```
easy_install-3.6 pip
```

Once installed you should see its location with the command:

```
$ which pip
/Library/Frameworks/Python.framework/Versions/3.6/bin/pip
```


# Installing pipx

`pipx` creates isolated environments for python applications.  That way, when 3rd party applications require different versions of a common package, the system doesn’t get polluted and unstable:

```
pip install pipx
```

Once pipx is installed, its `bin/` directory can be added to the `PATH` with the command:

```
pipx ensurepath
```

These are the only packages installed at the system level.  Now, everything else is installed with `pipx`

Like with the Python install above, close out of the current shell and launch a new one.  When you run `echo $PATH` you should see `${HOME}/.local/bin` in the path.


# Installing 3rd party packages

There is one important package for development that should be installed: `pipenv`:

```
pipx install pipenv
```

Once that command is run, `which pipenv` should produce something similar to:

```
$ which pipenv
${HOME}/.local/bin/pipenv
```

From here, development on a project should be done with pipenv


# More 3rd party things

Another useful 3rd party application is the AWS command line tools.  With the install covered here, that can be installed with the command `pipx install awscli`, and it will show up like so:

```
$ which aws
/Users/berto/.local/bin/aws
```