human
I wrote the below code

    def FixPath(path):
        path = gyp.common.FixIfRelativePath(path, options.depth)
        if (not path):
            return os.path.curdir
        return path
    def Noop(value):
        return value
    flags = ['--ignore-environment']
    for (name, metadata) in options._regeneration_metadata.iteritems():
        opt = metadata['opt']
        value = getattr(options, name)
        value_predicate = (((metadata['type'] == 'path') and FixPath) or Noop)
        action = metadata['action']
        env_name = metadata['env_name']
        if (action == 'append'):
            flags.extend(RegenerateAppendFlag(opt, value, value_predicate, env_name, options))
        elif (action in ('store', None)):
            if value:
                flags.append(FormatOpt(opt, value_predicate(value)))
            elif (options.use_environment and env_name and os.environ.get(env_name)):
                flags.append(FormatOpt(opt, value_predicate(os.environ.get(env_name))))
        elif (action in ('store_true', 'store_false')):
            if (((action == 'store_true') and value) or ((action == 'store_false') and (not value))):
                flags.append(opt)
            elif (options.use_environment and env_name):
                print >>sys.stderr, ('Warning:    environment    regeneration    unimplemented    for    %s    flag    %r    env_name    %r' % (action, opt, env_name))
        else:
            print >>sys.stderr, ('Warning:    regeneration    unimplemented    for    action    %r    flag    %r' % (action, opt))
    return flags

What's a good function header?

=====
What is a Python code to print >>sys?
assistant
#Here is Python code to print >>sys.

def RegenerateFlags(options):