title: How can I prevent a name error error in python?
body: <p>When I run my program core.py (<a href="http://pastebin.com/kbzbBUYd" rel="nofollow noreferrer">http://pastebin.com/kbzbBUYd</a>) it returns:</p>
  
  <p>File "core.py", line 47, in texto
      core.mail(numbersendlist, messagetext)
  NameError: global name 'core' is not defined</p>
  
  <p>Can anyone tell me what is going on and how I can stop this error?</p>
  
  <p>If it helps, the "import carrier" line in core.py refers to carrier.py (<a href="http://pastebin.com/zP2RHbnr" rel="nofollow noreferrer">http://pastebin.com/zP2RHbnr</a>)</p>