Troubleshooting errors while trying to install pip

error

PS C:\Python27\ArcGIS10.2\Lib\site-packages> python get-pip.py
Traceback (most recent call last):
  File "get-pip.py", line 20204, in <module>
    main()
  File "get-pip.py", line 152, in main
    bootstrap(tmpdir=tmpdir)
  File "get-pip.py", line 82, in bootstrap
    import pip
  File "c:\users\ryanco~1\appdata\local\temp\tmpbwqs3j\pip.zip\pip\__init__.py", line 13, in <module>
  File "c:\users\ryanco~1\appdata\local\temp\tmpbwqs3j\pip.zip\pip\utils\__init__.py", line 22, in <module>
  File "c:\users\ryanco~1\appdata\local\temp\tmpbwqs3j\pip.zip\pip\_vendor\__init__.py", line 61, in load_module
  File "c:\users\ryanco~1\appdata\local\temp\tmpbwqs3j\pip.zip\pip\_vendor\pkg_resources\__init__.py", line 79, in <module>
  File "c:\users\ryanco~1\appdata\local\temp\tmpbwqs3j\pip.zip\pip\_vendor\packaging\specifiers.py", line 274, in <module>
  File "c:\users\ryanco~1\appdata\local\temp\tmpbwqs3j\pip.zip\pip\_vendor\packaging\specifiers.py", line 373, in Specifier
  File "C:\Python27\ArcGIS10.2\lib\re.py", line 190, in compile return _compile(pattern, flags)
  File "C:\Python27\ArcGIS10.2\lib\re.py", line 242, in _compile raise error, v # invalid expression
sre_constants.error: nothing to repeat