title: Python regex is hung up when creating a group and certain characters followed by digits
body: <p>I am getting a weird situation in Python 3. Attempting to find some characters (a-z) that have one period and space(s) in between followed by a section sign (0-2 times) followed by a space, followed by digits (1 or more times).</p>
  
  <p>When running this in Python, I don't get a result. It just get hung up.</p>
  
  <pre><code>import re
  string = "Guidelines on International Protection: Membership in a “Particular Social Group” Within the Context of Article 1A(2) of the 1951 Convention and/or its 1967 Protocol Relating to the Status 
      ...: of Refugees (UNHCR Guidelines), U.N. Doc. HCR/GIP/02/02 (May 7, 2002)"
  regex = r'((?:[a-z]+\.{0,1}\s*)+)(§{0,2})\s+(\d+)'
  compile = re.compile(regex, flags=re.IGNORECASE)  
  re.findall(compile,string)
  
  </code></pre>
  
  <p>In <a href="https://regexr.com/" rel="nofollow noreferrer">https://regexr.com/</a>, it actually gives me correct matches: <a href="https://regexr.com/53394" rel="nofollow noreferrer">https://regexr.com/53394</a></p>
  
  <p>What is happening?</p>