Python version conflicts and pip3
<p>It is a tough situation I am dealing with. Here is short version of my problem:</p>

<ul>
<li>I am working on Ubuntu 12.04</li>
<li>I would like to install <code>Python 3.5.x</code> with <code>openCV</code> library. I would also like to use <code>pip3</code> for managing package installation of python. </li>
</ul>

<p><strong>Here is how the version of my pythons looks like</strong></p>

<pre><code>    $ python --version
      Python 2.7.3
    $ python3 --version
      Python 3.5.2
</code></pre>

<p>So far it looks I have achieved my goal.</p>

<p><strong>When I use <code>virtualenv</code> to  manage <code>python3</code> libraries:</strong></p>

<pre><code>   virtualenv -p /usr/bin/python3 py3env
   source py3env/bin/activate
</code></pre>

<p>I see the version of my python as follows:</p>

<pre><code>   (py3env)yxxxxa@yxxxxa-Precision-M4800:~$ python3 --version
    Python 3.2.3
</code></pre>

<p>I seems there is another version of python in my machine <code>3.2.3</code> messing up with the version <code>3.5.2</code> that I have installed. This is my first problem.</p>

<p><strong>The second related problem is that I am unable to install <code>pip 3</code>. There is this error I receive due to the same python version conflict:</strong></p>

<pre><code> $ pip
/usr/local/lib/python3.2/dist-packages/pip-8.1.2-py3.2.egg/pip/_vendor /pkg_resources/__init__.py:80: UserWarning: Support for Python 3.0-3.2 has been dropped. Future versions will fail here.
  warnings.warn(msg)
 Traceback (most recent call last):
   File "/usr/local/bin/pip", line 9, in &lt;module&gt;
 load_entry_point('pip==8.1.2', 'console_scripts', 'pip')()
   File "/usr/lib/python3/dist-packages/pkg_resources.py", line 337, in  load_entry_point
 return get_distribution(dist).load_entry_point(group, name)
   File "/usr/lib/python3/dist-packages/pkg_resources.py", line 2280, in load_entry_point
 return ep.load()
    File "/usr/lib/python3/dist-packages/pkg_resources.py", line 1990, in load
  entry = __import__(self.module_name, globals(),globals(), ['__name__'])
    File "/usr/local/lib/python3.2/dist-packages/pip-8.1.2-py3.2.egg/pip/__init__.py", line 16, in &lt;module&gt;
   from pip.vcs import git, mercurial, subversion, bazaar  # noqa
    File "/usr/local/lib/python3.2/dist-packages/pip-8.1.2-py3.2.egg/pip/vcs/mercurial.py", line 9, in &lt;module&gt;
   from pip.download import path_to_url
    File "/usr/local/lib/python3.2/dist-packages/pip-8.1.2-py3.2.egg/pip/download.py", line 36, in &lt;module&gt;
   from pip.utils.ui import DownloadProgressBar, DownloadProgressSpinner
    File "/usr/local/lib/python3.2/dist-packages/pip-8.1.2-py3.2.egg/pip/utils/ui.py", line 15, in &lt;module&gt;
   from pip._vendor.progress.bar import Bar, IncrementalBar
    File "/usr/local/lib/python3.2/dist-packages/pip-8.1.2-py3.2.egg/pip/_vendor/progress/bar.py", line 48
empty_fill = u'â'
                  ^
   SyntaxError: invalid syntax
   yasharatena@yasharatena-Precision-M4800:~$ pip3
  /usr/local/lib/python3.2/dist-packages/pip-8.1.2-py3.2.egg/pip/_vendor/pkg_resources/__init__.py:80: UserWarning: Support for Python 3.0-3.2 has been dropped. Future versions will fail here.
   warnings.warn(msg)
   Traceback (most recent call last):
    File "/usr/local/bin/pip3", line 9, in &lt;module&gt;
   load_entry_point('pip==8.1.2', 'console_scripts', 'pip3')()
    File "/usr/lib/python3/dist-packages/pkg_resources.py", line 337, in load_entry_point
   return get_distribution(dist).load_entry_point(group, name)
    File "/usr/lib/python3/dist-packages/pkg_resources.py", line 2280, in  load_entry_point
   return ep.load()
   File "/usr/lib/python3/dist-packages/pkg_resources.py", line 1990, in load
   entry = __import__(self.module_name, globals(),globals(), ['__name__'])
   File "/usr/local/lib/python3.2/dist-packages/pip-8.1.2-py3.2.egg/pip/__init__.py", line 16, in &lt;module&gt;
    from pip.vcs import git, mercurial, subversion, bazaar  # noqa
    File "/usr/local/lib/python3.2/dist-packages/pip-8.1.2-py3.2.egg/pip/vcs/mercurial.py", line 9, in &lt;module&gt;
from pip.download import path_to_url
    File "/usr/local/lib/python3.2/dist-packages/pip-8.1.2-py3.2.egg/pip/download.py", line 36, in &lt;module&gt;
    from pip.utils.ui import DownloadProgressBar, DownloadProgressSpinner
    File "/usr/local/lib/python3.2/dist-packages/pip-8.1.2-py3.2.egg/pip/utils/ui.py", line 15, in &lt;module&gt;
    from pip._vendor.progress.bar import Bar, IncrementalBar
    File "/usr/local/lib/python3.2/dist-packages/pip-8.1.2-py3.2.egg/pip/_vendor/progress/bar.py", line 48
    empty_fill = u'â'
                  ^
    SyntaxError: invalid syntax
</code></pre>

<p>What are your expert opinions about the stated problem? Any cool idea to handle this? Thanks alot in advance</p>

<blockquote>
  <p>This solved my first problem. Now the second problem aslo remains, how
  can I install pip3 under python 3.5.2 (preferably using viretualenv) ?</p>
</blockquote>

<p>Here is answer:</p>

<pre><code>python3 -m virtualenv py3env

source py3env/bin/activate
</code></pre>

<p>Python 3.5 should have pip by default, also after above commands You can use pip:) </p>

<p>For example :</p>

<pre><code>python -m pip install requests
</code></pre>

<p>EDIT:</p>

<p><a href="http://stackoverflow.com/questions/6587507/how-to-install-pip-with-python-3">Here</a> You could find very good explainations if You still need install pip after create virtualenv.</p>

python python-3.x pip