Сервер MongoDB не работает

Попытка читаемого пользователем регулярного выражения:

import re

regex = re.compile(r"""
    # name starts and ends on word boundary
    # no '(' or commas in the name
    (?P<name>\b[^(,]+\b)
    \s*
    # everything inside parentheses is a role
    (?:\(
      (?P<role>[^)]+)
    \))? # role is optional
    """, re.VERBOSE)

s = ("Wilbur Smith (Billy, son of John), Eddie Murphy (John), Elvis Presley,"
     "Jane Doe (Jane Doe)")
print re.findall(regex, s)

Выход:

[('Wilbur Smith', 'Billy, son of John'), ('Eddie Murphy', 'John'), 
 ('Elvis Presley', ''), ('Jane Doe', 'Jane Doe')]