__init__.py 文件源码

def number_of_colors(self):
        """Return the number of colors the terminal supports.

        Common values are 0, 8, 16, 88, and 256.

        Though the underlying capability returns -1 when there is no color
        support, we return 0. This lets you test more Pythonically::

            if term.number_of_colors:
                ...

        We also return 0 if the terminal won't tell us how many colors it
        supports, which I think is rare.

        """
        # This is actually the only remotely useful numeric capability. We
        # don't name it after the underlying capability, because we deviate
        # slightly from its behavior, and we might someday wish to give direct
        # access to it.
        colors = tigetnum('colors')  # Returns -1 if no color support, -2 if no
                                     # such cap.
        #  self.__dict__['colors'] = ret  # Cache it. It's not changing.
                                          # (Doesn't work.)
        return colors if colors >= 0 else 0