title: how to use pip in python
body: <p>I'm trying to use python-telegram-bot. (The version of python is 3)
  I installed it using 
  <code>pip install python-telegram-bot</code></p>
  
  <p>I run a file with the next code:</p>
  
  <pre><code>from telegram import Updater
  </code></pre>
  
  <p>And I get the next error:</p>
  
  <pre><code>Traceback (most recent call last):
  File "pyStart.py", line 1, in &lt;module&gt;
  from telegram import Updater
  ModuleNotFoundError: No module named 'telegram'
  </code></pre>
  
  <p>Even when using <code>from python-telegram-bot</code>, I get an error</p>
  
  <pre><code>File "pyStart.py", line 1
  from python-telegram-bot import Updater
             ^
  SyntaxError: invalid syntax
  </code></pre>
  
  <p>What causes the error?</p>