class_docstr: A collection of options, a dictionary with object-like access.
  
  Normally accessed via static functions in the `tornado.options` module,
  which reference a global instance.
class_docstr_tok: ["A","collection","of","options",",","a","dictionary","with","object-like","access",".","Normally","accessed","via","static","functions","in","the","`","tornado.options","`","module",",","which","reference","a","global","instance","."]
docstr: Prints all the command line options to stderr (or another file).
code: def print_help(self, file=None):
      """Prints all the command line options to stderr (or another file)."""
      if file is None:
          file = sys.stderr
      print("Usage: %s [OPTIONS]" % sys.argv[0], file=file)
      print("\nOptions:\n", file=file)
      by_group = {}
      for option in self._options.values():
          by_group.setdefault(option.group_name, []).append(option)
  
      for filename, o in sorted(by_group.items()):
          if filename:
              print(
                  "\n%s options:\n" % os.path.normpath(filename),
                  file=file,
              )
          o.sort(key=lambda option: option.name)
          for option in o:
              # Always print names with dashes in a CLI context.
              prefix = self._normalize_name(option.name)
              if option.metavar:
                  prefix += "=" + option.metavar
              description = option.help or ""
              if option.default is not None and option.default != "":
                  description += " (default %s)" % option.default
              lines = textwrap.wrap(description, 79 - 35)
              if len(prefix) > 30 or len(lines) == 0:
                  lines.insert(0, "")
              print("  --%-30s %s" % (prefix, lines[0]), file=file)
              for line in lines[1:]:
                  print("%-34s %s" % (" ", line), file=file)
      print(file=file)
  
imports: from __future__ import absolute_import, division, print_function
  import datetime
  import numbers
  import re
  import sys
  import os
  import textwrap
  from tornado.escape import _unicode, native_str
  from tornado.log import define_logging_options
  from tornado import stack_context
  from tornado.util import basestring_type, exec_in
label_desc: Use image node_id 16 for calling the OptionParser obj's underlying member method code with example usage: obj.print_help(file) without return types