parameters: (self, pat)
return_statement: return pat
docstring: Substitute a regular expression which matches no version
          or extension names for None or the empty string.
docstring_summary: Substitute a regular expression which matches no version
          or extension names for None or the empty string.
docstring_tokens: Substitute a regular expression which matches no version or extension names for None or the empty string .
function: def emptyRegex(self, pat):
          """Substitute a regular expression which matches no version
          or extension names for None or the empty string."""
          if not pat:
              return '_nomatch_^'
  
          return pat
function_tokens: def emptyRegex ( self , pat ) : if not pat : return '_nomatch_^' return pat