Line contains NULL byte while uninstalling Flask

Uninstalling flask or any library using this command gives contains null byte error exception

Command:

pip uninstall Flask

Error:

Exception:
Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/pip/basecommand.py", line 215, in main
    status = self.run(options, args)
  File "/usr/lib/python2.7/dist-packages/pip/commands/uninstall.py", line 76, in run
    requirement_set.uninstall(auto_confirm=options.yes)
  File "/usr/lib/python2.7/dist-packages/pip/req/req_set.py", line 346, in uninstall
    req.uninstall(auto_confirm=auto_confirm)
  File "/usr/lib/python2.7/dist-packages/pip/req/req_install.py", line 694, in uninstall
    for path in pip.wheel.uninstallation_paths(dist):
  File "/usr/lib/python2.7/dist-packages/pip/wheel.py", line 534, in unique
    for item in fn(*args, **kw):
  File "/usr/lib/python2.7/dist-packages/pip/wheel.py", line 554, in uninstallation_paths
    for row in r:
Error: line contains NULL byte

System: Raspberry Pi
OS Raspbian
Python2.7
pip 9

I will require to run code in python2 only

How do i resolve this issue?