Error while installing plotly even though it shows pip and plotly are successfully upgraded

I am new to python world. I am trying to install plotly to explore visualization. I installed pip. upgraded it. after that, I downloaded plotly. However, while importing it, it still shows error.

!python -m pip install --upgrade pip

It showed,

Collecting pip
  Using cached pip-9.0.1-py2.py3-none-any.whl
Installing collected packages: pip
  Found existing installation: pip 7.0.3
    Uninstalling pip-7.0.3:
      Successfully uninstalled pip-7.0.3
  Rolling back uninstall of pip
You are using pip version 7.0.3, however version 9.0.1 is available.
You should consider upgrading via the 'python -m pip install --upgrade pip' command.
Exception:
Traceback (most recent call last):
  File "C:\Python27\lib\site-packages\pip-7.0.3-py2.7.egg\pip\basecommand.py", line 223, in main
    status = self.run(options, args)
  File "C:\Python27\lib\site-packages\pip-7.0.3-py2.7.egg\pip\commands\install.py", line 297, in run
    root=options.root_path,
  File "C:\Python27\lib\site-packages\pip-7.0.3-py2.7.egg\pip\req\req_set.py", line 622, in install
    **kwargs
  File "C:\Python27\lib\site-packages\pip-7.0.3-py2.7.egg\pip\req\req_install.py", line 808, in install
    self.move_wheel_files(self.source_dir, root=root)
  File "C:\Python27\lib\site-packages\pip-7.0.3-py2.7.egg\pip\req\req_install.py", line 1003, in move_wheel_files
    isolated=self.isolated,
  File "C:\Python27\lib\site-packages\pip-7.0.3-py2.7.egg\pip\wheel.py", line 449, in move_wheel_files
    generated.extend(maker.make(spec))
  File "C:\Python27\lib\site-packages\pip-7.0.3-py2.7.egg\pip\_vendor\distlib\scripts.py", line 323, in make
    self._make_script(entry, filenames, options=options)
  File "C:\Python27\lib\site-packages\pip-7.0.3-py2.7.egg\pip\_vendor\distlib\scripts.py", line 227, in _make_script
    self._write_script(scriptnames, shebang, script, filenames, ext)
  File "C:\Python27\lib\site-packages\pip-7.0.3-py2.7.egg\pip\_vendor\distlib\scripts.py", line 163, in _write_script
    launcher = self._get_launcher('t')
  File "C:\Python27\lib\site-packages\pip-7.0.3-py2.7.egg\pip\_vendor\distlib\scripts.py", line 302, in _get_launcher
    result = finder(distlib_package).find(name).bytes
AttributeError: 'NoneType' object has no attribute 'bytes'

I upgraded pip,

!python -m pip install --upgrade pip

it shows,

Requirement already up-to-date: pip in c:\python27\lib\site-packages

After,

!pip install plotly --upgrade

it showed,

Requirement already up-to-date: plotly in c:\python27\lib\site-packages
Requirement already up-to-date: requests in c:\python27\lib\site-packages (from plotly)
Collecting six (from plotly)
  Downloading six-1.10.0-py2.py3-none-any.whl
Requirement already up-to-date: pytz in c:\python27\lib\site-packages (from plotly)
Installing collected packages: six
  Found existing installation: six 1.9.0
    Uninstalling six-1.9.0:
      Successfully uninstalled six-1.9.0
Successfully installed six-1.10.0
You are using pip version 7.0.3, however version 9.0.1 is available.
You should consider upgrading via the 'python -m pip install --upgrade pip' command.

when I am importing plotly,

import plotly

It shows,

No module named plotly

I aplogozise for the long question. But how should I deal with this? Is there something to do with API key?

I generated my API key and tried with

plotly.tools.set_credentials_file(username='DemoAccount', api_key='hcv50j3UCMhj6Q0iRXZr')

it says plotly is not defined. is it the correct syntax? Can someone please tell me step by step process roght from pip? Is there other way around?

Thank you.