title: How to check if phone number entered by user includes country code?
body: <p>Is there an easy way to check whether a phone number entered by the user includes country code and to validate that the number is correct? I don't use any specific formats, the number itself must be only digits, no ('s, -'s and the like. Is such validation possible without asking user for a country? The trick is that I want to work with all numbers world-wide. </p>
  
  <p>I guess it can't be done with regex (googled a bit and found lots of stuff but not for this problem). Is there any library for it? I'm using python. </p>
  
  <p>Or maybe it would make more sense to enforce a format e.g. X-YYYYYYYY... where X would be a country code, or something like this?</p>