¿Cómo instalar pip en OS X El Capitan?

Soy un nuevo usuario de Mac y necesito ayuda para intentar instalar pip en OS X El Capitan.

Ejecuté este comando, python get-pip.py y terminé con este error:

Exception:
Traceback (most recent call last):
  File "/var/folders/hc/87zml1_52jd544j9cd71mqrh0000gn/T/tmp83m3F3/pip.zip/pip/basecommand.py", line 215, in main
    status = self.run(options, args)
  File "/var/folders/hc/87zml1_52jd544j9cd71mqrh0000gn/T/tmp83m3F3/pip.zip/pip/commands/install.py", line 317, in run
    prefix=options.prefix_path,
  File "/var/folders/hc/87zml1_52jd544j9cd71mqrh0000gn/T/tmp83m3F3/pip.zip/pip/req/req_set.py", line 742, in install
    **kwargs
  File "/var/folders/hc/87zml1_52jd544j9cd71mqrh0000gn/T/tmp83m3F3/pip.zip/pip/req/req_install.py", line 831, in install
    self.move_wheel_files(self.source_dir, root=root, prefix=prefix)
  File "/var/folders/hc/87zml1_52jd544j9cd71mqrh0000gn/T/tmp83m3F3/pip.zip/pip/req/req_install.py", line 1032, in move_wheel_files
    isolated=self.isolated,
  File "/var/folders/hc/87zml1_52jd544j9cd71mqrh0000gn/T/tmp83m3F3/pip.zip/pip/wheel.py", line 346, in move_wheel_files
    clobber(source, lib_dir, True)
  File "/var/folders/hc/87zml1_52jd544j9cd71mqrh0000gn/T/tmp83m3F3/pip.zip/pip/wheel.py", line 317, in clobber
    ensure_dir(destdir)
  File "/var/folders/hc/87zml1_52jd544j9cd71mqrh0000gn/T/tmp83m3F3/pip.zip/pip/utils/__init__.py", line 83, in ensure_dir
    os.makedirs(path)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/os.py", line 157, in makedirs
    mkdir(name, mode)
OSError: [Errno 13] Permission denied: '/Library/Python/2.7/site-packages/pip'