Python 2.7 尝试执行pip卸载时出现操作不允许错误。如何解决？

操作系统：macOS Sierra

Python 2.7.10

我正在尝试清理所有python库。我试图这样做，同时试图解决这里提到的另一个问题

$sudo pip freeze | xargs pip卸载-y
当前用户不拥有目录“/Users/sa/Library/Caches/pip/http”或其父目录，缓存已被禁用。请检查该目录的权限和所有者。如果使用sudo执行pip，您可能需要sudo的-H标志。
卸载altgraph-0.10.2：
例外情况：
回溯（最近一次呼叫最后一次）：
文件“/Library/Python/2.7/site packages/pip-9.0.1-py2.7.egg/pip/basecommand.py”，第215行，在main中
status=self.run（选项、参数）
文件“/Library/Python/2.7/site packages/pip-9.0.1-py2.7.egg/pip/commands/uninstall.py”，第76行，运行中
需求设置。卸载（自动确认=选项。是）
卸载中第346行的文件“/Library/Python/2.7/site packages/pip-9.0.1-py2.7.egg/pip/req/req_set.py”
要求卸载（自动确认=自动确认）
卸载中第754行的文件“/Library/Python/2.7/site packages/pip-9.0.1-py2.7.egg/pip/req/req_install.py”
路径到移除。移除（自动确认）
文件“/Library/Python/2.7/site packages/pip-9.0.1-py2.7.egg/pip/req/req_uninstall.py”，删除中的第115行
重命名（路径，新路径）
文件“/Library/Python/2.7/site packages/pip-9.0.1-py2.7.egg/pip/utils/_init___;.py”，第267行，在重命名中
shutil.移动（旧、新）
文件“/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py”，第299行，移动中
复制树（src，real_dst，symlinks=True）
copytree中的文件“/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/shutil.py”，第208行
提出错误
错误：[（'/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/Python/altgraph/_init__.py'，'/var/folders/br/cmwb0g109n9f6sb268gfh75g1kljc/T/pip-Qvf8FD-uninstall/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/Python/altgraph/_uinit.py/_u init.py'，“[Errno 1]不允许操作：“/var/folders/br/cmwb0g0109n9f6sb268gfh75g1kljc/T/pip-Qvf8FD-uninstall/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/Python/altgraph/uu init_uu.py”，（“/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/Python/altgraph/uu init_u.pyc”、“/var/folders/br/cmwb0g0109n9f6sb268gfh75g1kljc/T/pip-Qvf8FD-uninstall/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/Python/altgraph/altraph/u init.pyc”、“[Errno 1]不允许操作：“/var/folders/br/cmwb0g0109n9f6sb268gfh75g1kljc/T/pip-Qvf8FD-uninstall/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/Python/altgraph/u_uinit_u.pyc”，（“/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/Python/altgraph/Dot.py'，”/var/folders/br/cmwb0g0109n9f6sb268gfh75g1kljc/T/pip-Qvf8FD-uninstall/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/Python/altgraph/Dot.py'，”[Errno 1]不允许操作：“/var/folders/br/cmwb0g0109n9f6sb268gfh75g1kljc/T/pip-Qvf8FD-uninstall/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/Python/altgraph/Dot.py”。”，（“/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/Python/altgraph/Dot.pyc”，“/var/folders/br/cmwb0g0109n9f6sb268gfh75g1kljc/T/pip-Qvf8FD-uninstall/System/Library/Frameworks/Python/2.7/Extras/lib/Python/altgraph/Dot.pyc”，”[Errno 1]不允许操作：“/var/folders/br/cmwb0g0109n9f6sb268gfh75g1kljc/T/pip-Qvf8FD-uninstall/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/Python/altgraph/Dot.pyc”。”，（“/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/Python/altgraph/Graph.py”，“/var/folders/br/cmwb0g0109n9f6sb268gfh75g1kljc/T/pip-Qvf8FD-uninstall/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/Python/altgraph/Graph.py”，”[Errno 1]不允许操作：“/var/folders/br/cmwb0g0109n9f6sb268gfh75g1kljc/T/pip-Qvf8FD-uninstall/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/Python/altgraph/Graph.py”。”，（“/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/Python/altgraph/Graph.pyc”，“/var/folders/br/cmwb0g0109n9f6sb268gfh75g1kljc/T/pip-Qvf8FD-uninstall/System/Library/Frameworks/Python/2.7/Extras/lib/Python/altgraph/Graph.pyc”，”[Errno 1]不允许操作：“/var/folders/br/cmwb0g0109n9f6sb268gfh75g1kljc/T/pip-Qvf8FD-uninstall/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/Python/altgraph/Graph.pyc”。”，（“/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/Python/altgraph/GraphAlgo.py'，”/var/folders/br/cmwb0g109n9f6sb268gfh75g1kljc/T/pip-Qvf8FD-uninstall/System/Library/Frameworks/Python/Versions/2.7/Extras/lib/Python/altgraph/GraphAlgo.py'，“[Errno 1]不允许操作：“/var/folders/br/cmwb0g0109n9f6sb268gfh75g1kljc/T/pip-Qvf8FD-uninstall/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/Python/altgraph/GraphAlgo.py”。”，（“/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/Python/altgraph/GraphAlgo.pyc”“，”/var/folders/br/cmwb0g109n9f6sb268gfh75g1kljc/T/pip-Qvf8FD-uninstall/System/Library/Frameworks/Python/Versions/2.7/Extras/lib/Python/altgraph/graph/GraphAlgo.pyc”“，“[Errno 1]不允许操作：“/var/folders/br/cmwb0g0109n9f6sb268gfh75g1kljc/T/pip-Qvf8FD-uninstall/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/Python/altgraph/GraphAlgo.pyc”。”，（“/System/Library/Frameworks/Python.framework/Versions/2.7/Extras/lib/Python/altgraph/GraphStat.py”，”/var/folders/br/cmwb0g109n9f6sb268gfh75g1kljc/T/pip-Qvf8FD-uninstall/System/Library/Frameworks/Python/Versions/2.7/Extras/lib/Python/altgraph/GraphStat.py'，“[Errno 1]不允许操作：'/var/folders/br/cmwb0g0109n9f6sb268gfh75g1kljc/T/pip-Qvf8FD-uninstall/System/Library/Frameworks/Python.framework/Versions/