title: ModuleNotFoundError: No module named 'xxx'; 'xxx' is not a package
body: <p>I am creating a project called OpenCity which contains a premium version. The premium package is the problem. </p>
  
  <p>The project hierarchy is:</p>
  
  <pre><code>opencity // is a project in PyCharm 2019.3
        premium // is a package
               __init__.py // is a module
               premium.py // is a module
               premium_user.py // is a module
               premium_user.txt // is a text file
  </code></pre>
  
  <p>premium_user.py:</p>
  
  <pre><code>import random as ran
  
  
  def premium_users_adder():
      premium_user1a = open('premium_user.txt', 'a')
      # premium_user1w = open('premium_user.txt', 'w')
      # premium_user1r = open('premium_user.txt', 'r')
      p2 = int(input("How many members do you want to add to premium_users to database? "))
      p1 = []
      p3 = []
      for i in range(p2):
          member = input("Type the person's name. ")
          p1.append(member)
          id1 = ran.randint(100000000, 99999999999)
          p3.append(str(id1))
      for i, e in zip(p1, p3):
          premium_user1a.write(i + ' ' + e + '\n')
      premium_user1a.close()
      print()
      print("Done")
  
  
  def premium_users_checker():
      premium_user1r = open('premium_user.txt', 'r')
      p2 = []
      for data in premium_user1r:
          p2.append(data)
          print(p2)
  
  </code></pre>
  
  <p>premium.py:</p>
  
  <pre><code>import premium.premium_users as pu
  pu.premium_users_adder()
  pu.premium_users_checker()
  </code></pre>
  
  <p>Error when running premium.py:</p>
  
  <pre><code>Traceback (most recent call last):
    File "F:/PyCharm Python Works/OpenCity/premium/premium.py", line 1, in &lt;module&gt;
      import premium.premium_users as pu
    File "F:\PyCharm Python Works\OpenCity\premium\premium.py", line 1, in &lt;module&gt;
      import premium.premium_users as pu
  ModuleNotFoundError: No module named 'premium.premium_users'; 'premium' is not a package
  
  </code></pre>
  
  <p>I have given everything except the <code>premium_users.txt</code> which contains premium codes.</p>