我正在按照以下说明在macOS上安装python库。

但是，每次运行此命令时，我都会收到错误消息： pip install --target=. Alfred-Workflow

而且我总是会因为运行它而收到此错误：

pip install --target=. Alfred-Workflow       
Collecting Alfred-Workflow
Installing collected packages: Alfred-Workflow
Exception:
Traceback (most recent call last):
  File "/usr/local/lib/python2.7/site-packages/pip/basecommand.py", line 215, in main
    status = self.run(options, args)
  File "/usr/local/lib/python2.7/site-packages/pip/commands/install.py", line 342, in run
    prefix=options.prefix_path,
  File "/usr/local/lib/python2.7/site-packages/pip/req/req_set.py", line 784, in install
    **kwargs
  File "/usr/local/lib/python2.7/site-packages/pip/req/req_install.py", line 851, in install
    self.move_wheel_files(self.source_dir, root=root, prefix=prefix)
  File "/usr/local/lib/python2.7/site-packages/pip/req/req_install.py", line 1064, in move_wheel_files
    isolated=self.isolated,
  File "/usr/local/lib/python2.7/site-packages/pip/wheel.py", line 247, in move_wheel_files
    prefix=prefix,
  File "/usr/local/lib/python2.7/site-packages/pip/locations.py", line 153, in distutils_scheme
    i.finalize_options()
  File "/usr/local/Cellar/python/2.7.13/Frameworks/Python.framework/Versions/2.7/lib/python2.7/distutils/command/install.py", line 264, in finalize_options
    "must supply either home or prefix/exec-prefix -- not both"
DistutilsOptionError: must supply either home or prefix/exec-prefix -- not both

我尝试使用谷歌搜索并进行搜索，但仍然无法解决。感谢您的任何帮助。