初學CNN，需要安裝sklearn庫進行資料訓練，但是提示我pip版本過低，於是嘗試更新pip，結果出現如下報錯

Exception:

Traceback (most recent call last):

  File "/Library/Python/2.7/site-packages/pip-9.0.1-py2.7.egg/pip/basecommand.py", line 215, in main

    status = self.run(options, args)

  File "/Library/Python/2.7/site-packages/pip-9.0.1-py2.7.egg/pip/commands/install.py", line 342, in run

    prefix=options.prefix_path,

  File "/Library/Python/2.7/site-packages/pip-9.0.1-py2.7.egg/pip/req/req_set.py", line 778, in install

    requirement.uninstall(auto_confirm=True)

  File "/Library/Python/2.7/site-packages/pip-9.0.1-py2.7.egg/pip/req/req_install.py", line 754, in uninstall

    paths_to_remove.remove(auto_confirm)

  File "/Library/Python/2.7/site-packages/pip-9.0.1-py2.7.egg/pip/req/req_uninstall.py", line 115, in remove

    renames(path, new_path)

  File "/Library/Python/2.7/site-packages/pip-9.0.1-py2.7.egg/pip/utils/__init__.py", line 267, in renames

    shutil.move(old, new)

  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py", line 300, in move

    rmtree(src)

  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py", line 247, in rmtree

    rmtree(fullname, ignore_errors, onerror)

  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py", line 252, in rmtree

    onerror(os.remove, fullname, sys.exc_info())

  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py", line 250, in rmtree

    os.remove(fullname)

OSError: [Errno 13] Permission denied: '/Library/Python/2.7/site-packages/pip-9.0.1-py2.7.egg/EGG-INFO/dependency_links.txt'

經過查詢，確實是我太naive了，這是一個很明顯的許可權問題，將命令加入sudo，改為

sudo pip install --upgrade pip