posix.py 文件源码

def __init__(self, devname=None):
        if devname is None:
            self.name = "/dev/urandom"
        else:
            self.name = devname

        # Test that /dev/urandom is a character special device
        f = open(self.name, "rb", 0)
        fmode = os.fstat(f.fileno())[stat.ST_MODE]
        if not stat.S_ISCHR(fmode):
            f.close()
            raise TypeError("%r is not a character special device" % (self.name,))

        self.__file = f

        BaseRNG.__init__(self)