title: ImportError in terminal for importing a module created in VS Code
body: <p>Created in VS Code a file containing a new class called Book. When I try and import it via terminal (on MacBook), I get this error message:</p>
  <blockquote>
  <p>ImportError: No module named Book.</p>
  </blockquote>
  <p>This is the VS Code code:</p>
  <pre class="lang-py prettyprint-override"><code>    class Book:
  
      def __init__(self, title):
          self.title = title
  </code></pre>
  <p>And the terminal:</p>
  <pre class="lang-py prettyprint-override"><code>    from book import Book
  </code></pre>
  <p>What causes this import error, and how do I fix this?</p>