尝试使用pip for python下载boto

我安装了pip sudo easy_install pip使得我可以为python加载boto.然后我做了pip install -U boto并且发生了这个错误

    Installing collected packages: boto
    Cleaning up...
    Exception:
    Traceback (most recent call last):
      File "/Library/Python/2.7/site-packages/pip-1.5.6-py2.7.egg/pip/basecommand.py", line 122, in main
        status = self.run(options, args)
      File "/Library/Python/2.7/site-packages/pip-1.5.6-py2.7.egg/pip/commands/install.py", line 283, in run
        requirement_set.install(install_options, global_options, root=options.root_path)
      File "/Library/Python/2.7/site-packages/pip-1.5.6-py2.7.egg/pip/req.py", line 1435, in install
        requirement.install(install_options, global_options, *args, **kwargs)
      File "/Library/Python/2.7/site-packages/pip-1.5.6-py2.7.egg/pip/req.py", line 671, in install
        self.move_wheel_files(self.source_dir, root=root)
      File "/Library/Python/2.7/site-packages/pip-1.5.6-py2.7.egg/pip/req.py", line 901, in move_wheel_files
        pycompile=self.pycompile,
      File "/Library/Python/2.7/site-packages/pip-1.5.6-py2.7.egg/pip/wheel.py", line 215, in move_wheel_files
        clobber(source, lib_dir, True)
      File "/Library/Python/2.7/site-packages/pip-1.5.6-py2.7.egg/pip/wheel.py", line 205, in clobber
        os.makedirs(destdir)
      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/boto'

    Storing debug log for failure in /Users/DRizzuto/Library/Logs/pip.log

所以我试着去做easy_install boto这个错误

The following error occurred while trying to add or remove files in the
installation directory:

    [Errno 13] Permission denied: '/Library/Python/2.7/site-packages/test-easy-install-2024.write-test'

The installation directory you specified (via --install-dir, --prefix, or
the distutils default setting) was:

    /Library/Python/2.7/site-packages/

Perhaps your account does not have write access to this directory?  If the
installation directory is a system-owned directory, you may need to sign in
as the administrator or "root" account.  If you do not have administrative
access to this machine, you may wish to choose a different installation
directory, preferably one that is listed in your PYTHONPATH environment
variable.

我现在不知道如何安装boto.有人可以解释我如何绕过或摆脱这些错误？