dist.py 文件源码

def handle_display_options(self, option_order):
        """If there were any non-global "display-only" options
        (--help-commands or the metadata display options) on the command
        line, display the requested info and return true; else return
        false.
        """
        import sys

        if six.PY2 or self.help_commands:
            return _Distribution.handle_display_options(self, option_order)

        # Stdout may be StringIO (e.g. in tests)
        import io
        if not isinstance(sys.stdout, io.TextIOWrapper):
            return _Distribution.handle_display_options(self, option_order)

        # Don't wrap stdout if utf-8 is already the encoding. Provides
        #  workaround for #334.
        if sys.stdout.encoding.lower() in ('utf-8', 'utf8'):
            return _Distribution.handle_display_options(self, option_order)

        # Print metadata in UTF-8 no matter the platform
        encoding = sys.stdout.encoding
        errors = sys.stdout.errors
        newline = sys.platform != 'win32' and '\n' or None
        line_buffering = sys.stdout.line_buffering

        sys.stdout = io.TextIOWrapper(
            sys.stdout.detach(), 'utf-8', errors, newline, line_buffering)
        try:
            return _Distribution.handle_display_options(self, option_order)
        finally:
            sys.stdout = io.TextIOWrapper(
                sys.stdout.detach(), encoding, errors, newline, line_buffering)