title: ModuleNotFoundError: No module named 'core' while PyCharm can run 'core.py'
body: <p>So I was trying to install a package called 'gdsCAD', and this is where I ended up:</p>
  <blockquote>
  <p>C:\Anaconda\python.exe
  &quot;C:/Users/HUANG/PycharmProjects/pythonProject2/trial1.py&quot;</p>
  <p>Traceback (most recent call last):</p>
  <p>File &quot;C:/Users/HUANG/PycharmProjects/pythonProject2/trial1.py&quot;, line
  2, in 
  import gdsCAD</p>
  <p>File &quot;C:\Anaconda\lib\site-packages\gdsCAD\_<em>init</em>_.py&quot;, line 26, in
  
  import core</p>
  <p>ModuleNotFoundError: No module named 'core'</p>
  </blockquote>
  <p>And these are the first lines of '_<em>init</em>_.py' which runs fine:</p>
  <pre><code>import core
  import shapes
  import utils
  import templates
  </code></pre>
  <p>I can also find the 'core.py' in the same folder which also runs fine. Somehow all these files can run individually, but error occurs when I import the whole package. Could you please shed some lights on it? Thanks!</p>