pip is showing error 'lsb_release -a' returned non-zero exit status 1

I am trying to install packages using pip and it is throwing error.

Command that I have used,

sudo pip install selenium

The error it is showing,

Exception:Traceback (most recent call last):  File "/usr/local/lib/python2.7/dist-packages/pip/basecommand.py", line 215, in main    status = self.run(options, args)  File "/usr/local/lib/python2.7/dist-packages/pip/commands/install.py", line 272, in run    with self._build_session(options) as session:  File "/usr/local/lib/python2.7/dist-packages/pip/basecommand.py", line 72, in _build_session    insecure_hosts=options.trusted_hosts,  File "/usr/local/lib/python2.7/dist-packages/pip/download.py", line 329, in __init__    self.headers["User-Agent"] = user_agent()  File "/usr/local/lib/python2.7/dist-packages/pip/download.py", line 93, in user_agent    from pip._vendor import distro  File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/distro.py", line 1050, in <module>    _distro = LinuxDistribution()  File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/distro.py", line 594, in __init__    if include_lsb else {}  File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/distro.py", line 933, in _get_lsb_release_info    raise subprocess.CalledProcessError(code, cmd, stdout)CalledProcessError: Command 'lsb_release -a' returned non-zero exit status 1Traceback (most recent call last):  File "/usr/local/bin/pip", line 11, in <module>    sys.exit(main())  File "/usr/local/lib/python2.7/dist-packages/pip/__init__.py", line 233, in main    return command.main(cmd_args)  File "/usr/local/lib/python2.7/dist-packages/pip/basecommand.py", line 251, in main    timeout=min(5, options.timeout)) as session:  File "/usr/local/lib/python2.7/dist-packages/pip/basecommand.py", line 72, in _build_session    insecure_hosts=options.trusted_hosts,  File "/usr/local/lib/python2.7/dist-packages/pip/download.py", line 329, in __init__    self.headers["User-Agent"] = user_agent()  File "/usr/local/lib/python2.7/dist-packages/pip/download.py", line 93, in user_agent    from pip._vendor import distro  File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/distro.py", line 1050, in <module>    _distro = LinuxDistribution()  File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/distro.py", line 594, in __init__    if include_lsb else {}  File "/usr/local/lib/python2.7/dist-packages/pip/_vendor/distro.py", line 933, in _get_lsb_release_info    raise subprocess.CalledProcessError(code, cmd, stdout)subprocess.CalledProcessError: Command 'lsb_release -a' returned non-zero exit status 1

I have searched everywhere, but there is no solution for this problem. It started behaving like this recently. Also, Software Updater stopped working. Not sure if it is related to that. I am using Ubuntu 14.04 LTS and python 2.X