input: Write a function that eliminates the portion of a string enclosed in parentheses.
  assert remove_parentheses(["python (chrome)"]) == "python"
  assert remove_parentheses(["string(.abc)"]) == "string"
  assert remove_parentheses(["alpha(num)"]) == "alpha"
output: def remove_parentheses(lst):
      s = lst[0]
      while '(' in s and ')' in s:
          start = s.rfind('(')
          end = s.find(')', start) + 1
          s = s[:start] + s[end:]
      return s.strip()