title: web3 installed but not accessible using python
body: <p>web3 is already installed (using pip3) but in different path.
  i tried many ways to import web3 but its shows no module named web3 everytime.</p>
  
  <p>i have already tried pip install as well as pip3 install but none is solving the issue.
  how can i solve the issue ?</p>
  
  <p>Python 3.5.0 (default, Aug 31 2018, 06:38:24)
  [GCC 5.4.0 20160609] on linux
  Type "help", "copyright", "credits" or "license" for more information.</p>
  
  <blockquote>
    <blockquote>
      <blockquote>
        <p>from web3 import Web3
        Traceback (most recent call last):
          File "", line 1, in 
        ImportError: No module named 'web3'</p>
      </blockquote>
    </blockquote>
  </blockquote>