更新pip的时候，以及使用pip安装python包的时候，注意权限
➜ ~ pip install --upgrade pip
Collecting pip
Downloading pip-9.0.1-py2.py3-none-any.whl (1.3MB)
100% |████████████████████████████████| 1.3MB 44kB/s
Installing collected packages: pip
Found existing installation: pip 8.0.2
Uninstalling pip-8.0.2:
Exception:
Traceback (most recent call last):
File "/usr/local/lib/python2.7/site-packages/pip/basecommand.py", line 209, in main
status = self.run(options, args)
File "/usr/local/lib/python2.7/site-packages/pip/commands/install.py", line 317, in run
prefix=options.prefix_path,
File "/usr/local/lib/python2.7/site-packages/pip/req/req_set.py", line 725, in install
requirement.uninstall(auto_confirm=True)
File "/usr/local/lib/python2.7/site-packages/pip/req/req_install.py", line 752, in uninstall
paths_to_remove.remove(auto_confirm)
File "/usr/local/lib/python2.7/site-packages/pip/req/req_uninstall.py", line 115, in remove
renames(path, new_path)
File "/usr/local/lib/python2.7/site-packages/pip/utils/__init__.py", line 266, in renames
shutil.move(old, new)
File "/usr/local/Cellar/python/2.7.11/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py", line 300, in move
rmtree(src)
File "/usr/local/Cellar/python/2.7.11/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py", line 252, in rmtree
onerror(os.remove, fullname, sys.exc_info())
File "/usr/local/Cellar/python/2.7.11/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py", line 250, in rmtree
os.remove(fullname)
OSError: [Errno 13] Permission denied: '/usr/local/lib/python2.7/site-packages/pip/__init__.py'
You are using pip version 8.0.2, however version 9.0.1 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
