docs: def babel2datetime(pattern):
      """Convert date format from babel (http://babel.pocoo.org/docs/dates/#date-
      fields)) to a format understood by datetime.strptime."""
      if not isinstance(pattern, DateTimePattern):
          pattern = parse_pattern(pattern)
  
      map_fmt = {
          # days
          "d": "%d",
          "dd": "%d",
          "EEE": "%a",
          "EEEE": "%A",
          "EEEEE": "%a",  # narrow name => short name
          # months
          "M": "%m",
          "MM": "%m",
          "MMM": "%b",
          "MMMM": "%B",
          # years
          "y": "%Y",
          "yy": "%Y",
          "yyyy": "%Y",
          # hours
          "h": "%I",
          "hh": "%I",
          "H": "%H",
          "HH": "%H",
          # minutes,
          "m": "%M",
          "mm": "%M",
          # seconds
          "s": "%S",
          "ss": "%S",
          # am/pm
          "a": "%p",
      }
  
      return pattern.format % map_fmt