解决方案
UPDATE: This is no longer necessary with Python3.4. It installs pip3 as part of the stock install.

I ended up posting this same question on the python mailing list, and got the following answer:

download and install setuptools

curl -O https://bootstrap.pypa.io/ez_setup.py
python3 ez_setup.py

download and install pip

curl -O https://bootstrap.pypa.io/get-pip.py
python3 get-pip.py
Which solved my question perfectly. After adding the following for my own:

cd /usr/local/bin
ln -s ../../../Library/Frameworks/Python.framework/Versions/3.3/bin/pip pip
So that I could run pip directly, I was able to:

use pip to install

pip install pyserial
or:

Don't want it?

pip uninstall pyserial

参考:

How to install pip for Python 3 on Mac OS X?
https://www.it1352.com/1587148.html

ln覆盖已经存在的软连接文件
http://blog.sina.com.cn/s/blog_1512521570102xvo5.html