title: Trouble with python3 and pip
body: <p>I'm on Linux Mint 18.3 Sylvia.
  I have an issue with pip and python3, and no other issues helped me actually.
  <code>dsds</code>
  Everything work when I do
  <code>python -m pip --version pip 8.1.1 from /usr/lib/python2.7/dist-packages (python 2.7) </code>
  But whenusing python3 doing
  <code>python3 -m pip --version</code></p>
  <p>I get the following message</p>
  <p><code>Traceback (most recent call last):   File &quot;/usr/lib/python3.5/runpy.py&quot;, line 184, in _run_module_as_main &quot;__main__&quot;, mod_spec) File &quot;/usr/lib/python3.5/runpy.py&quot;, line 85, in _run_code exec(code, run_globals) File &quot;/home/max/.local/lib/python3.5/site-packages/pip/__main__.py&quot;, line 21, in &lt;module&gt; from pip._internal.cli.main import main as _main File &quot;/home/max/.local/lib/python3.5/site-packages/pip/_internal/cli/main.py&quot;, line 60 sys.stderr.write(f&quot;ERROR: {exc}&quot;) ^ SyntaxError: invalid syntax </code></p>
  <p>Any ideas to how solve this ? Thanks you!</p>
  <p>edit: python command is Python 2.7.12</p>
  <p>edit2: I originally wanted to install matplotlib as described <a href="https://matplotlib.org/users/installing.html#installing-an-official-release" rel="nofollow noreferrer">here</a>. By using the command <code>python -m pip install -U pip</code> as told in the installation process. This is probably the issue, as now it show the error for both python and python3 command...</p>