title: Python cannot find flask package which is installed
body: <p>When I run my flask project on my server, I get the following error:</p>
  
  <pre><code>Traceback (most recent call last):
    File "File.py", line 1, in &lt;module&gt;
      from flask import Flask, request
  ImportError: No module named 'flask'
  </code></pre>
  
  <p>But I have flask installed!</p>
  
  <pre><code>$sudo pip install flask
  Requirement already satisfied: flask in /usr/local/lib/python2.7/dist-packages
  Requirement already satisfied: itsdangerous&gt;=0.21 in /usr/local/lib/python2.7/dist-packages (from flask)
  Requirement already satisfied: click&gt;=2.0 in /usr/local/lib/python2.7/dist-packages (from flask)
  Requirement already satisfied: Werkzeug&gt;=0.7 in /usr/local/lib/python2.7/dist-packages (from flask)
  Requirement already satisfied: Jinja2&gt;=2.4 in /usr/local/lib/python2.7/dist-packages (from flask)
  Requirement already satisfied: MarkupSafe&gt;=0.23 in /usr/local/lib/python2.7/dist-packages (from Jinja2&gt;=2.4-&gt;flask)
  </code></pre>
  
  <p>This is driving me crazy. I've tried what other SO answers have suggested, including using a venv, but they all produce this same error. Anyone have a suggestion?</p>
  
  <pre><code>$ which python
  /usr/bin/python
  $ which python3
  /usr/bin/python3
  </code></pre>
  
  <p>I'm running python 3.5.2</p>