How can I fix this error showing up when using pip install wit

Question

I was trying to install wit.ai using pip but I got the following error code:

pip install wit

Exception:
Traceback (most recent call last):
  File "C:\Python27\lib\site-packages\pip\basecommand.py", line 122, in main
    status = self.run(options, args)
  File "C:\Python27\lib\site-packages\pip\commands\install.py", line 278, in run
    requirement_set.prepare_files(finder, force_root_egg_info=self.bundle, bundle=self.bundle)
  File "C:\Python27\lib\site-packages\pip\req.py", line 1265, in prepare_files
    req_to_install.extras):
  File "C:\Python27\lib\site-packages\pip\_vendor\pkg_resources.py", line 2291, in requires
    dm = self._dep_map
  File "C:\Python27\lib\site-packages\pip\_vendor\pkg_resources.py", line 2484, in _dep_map
    self.__dep_map = self._compute_dependencies()
  File "C:\Python27\lib\site-packages\pip\_vendor\pkg_resources.py", line 2508, in _compute_dependencies
    parsed = next(parse_requirements(distvers))
  File "C:\Python27\lib\site-packages\pip\_vendor\pkg_resources.py", line 45, in <lambda>
    next = lambda o: o.next()
  File "C:\Python27\lib\site-packages\pip\_vendor\pkg_resources.py", line 2605, in parse_requirements
    line, p, specs = scan_list(VERSION,LINE_END,line,p,(1,2),"version spec")
  File "C:\Python27\lib\site-packages\pip\_vendor\pkg_resources.py", line 2573, in scan_list
    raise ValueError("Expected "+item_name+" in",line,"at",line[p:])
ValueError: ('Expected version spec in', 'charset-normalizer ~=2.0.0', 'at', ' ~=2.0.0')