Pip installs third-party module time error - Codes Helper

C:\Users\changhao>pip install apscheduler
Collecting apscheduler
Exception:
Traceback (most recent call last):
  File "c:\users\changhao\appdata\local\programs\python\python36\lib\site-packages\pip\_internal\cli\base_command.py", line 143, in main
    status = self.run(options, args)
  File "c:\users\changhao\appdata\local\programs\python\python36\lib\site-packages\pip\_internal\commands\install.py", line 318, in run
    resolver.resolve(requirement_set)
  File "c:\users\changhao\appdata\local\programs\python\python36\lib\site-packages\pip\_internal\resolve.py", line 102, in resolve
    self._resolve_one(requirement_set, req)
  File "c:\users\changhao\appdata\local\programs\python\python36\lib\site-packages\pip\_internal\resolve.py", line 256, in _resolve_one
    abstract_dist = self._get_abstract_dist_for(req_to_install)
  File "c:\users\changhao\appdata\local\programs\python\python36\lib\site-packages\pip\_internal\resolve.py", line 209, in _get_abstract_dist_for
    self.require_hashes
  File "c:\users\changhao\appdata\local\programs\python\python36\lib\site-packages\pip\_internal\operations\prepare.py", line 218, in prepare_linked_requirement
    req.populate_link(finder, upgrade_allowed, require_hashes)
  File "c:\users\changhao\appdata\local\programs\python\python36\lib\site-packages\pip\_internal\req\req_install.py", line 164, in populate_link
    self.link = finder.find_requirement(self, upgrade)
  File "c:\users\changhao\appdata\local\programs\python\python36\lib\site-packages\pip\_internal\index.py", line 572, in find_requirement
    all_candidates = self.find_all_candidates(req.name)
  File "c:\users\changhao\appdata\local\programs\python\python36\lib\site-packages\pip\_internal\index.py", line 530, in find_all_candidates
    for page in self._get_pages(url_locations, project_name):
  File "c:\users\changhao\appdata\local\programs\python\python36\lib\site-packages\pip\_internal\index.py", line 675, in _get_pages
    page = self._get_page(location)
  File "c:\users\changhao\appdata\local\programs\python\python36\lib\site-packages\pip\_internal\index.py", line 793, in _get_page
    return _get_html_page(link, session=self.session)
  File "c:\users\changhao\appdata\local\programs\python\python36\lib\site-packages\pip\_internal\index.py", line 144, in _get_html_page
    "Cache-Control": "max-age=0",
TypeError: get() got an unexpected keyword argument "headers"