gdal.py 文件源码

def BeginAsyncReader(self, xoff, yoff, xsize, ysize, buf_obj = None, buf_xsize = None, buf_ysize = None, buf_type = None, band_list = None, options=[]):
        if band_list is None:
            band_list = range(1, self.RasterCount + 1)
        if buf_xsize is None:
            buf_xsize = 0;
        if buf_ysize is None:
            buf_ysize = 0;
        if buf_type is None:
            buf_type = GDT_Byte

        if buf_xsize <= 0:
            buf_xsize = xsize
        if buf_ysize <= 0:
            buf_ysize = ysize

        if buf_obj is None:
            from sys import version_info
            nRequiredSize = int(buf_xsize * buf_ysize * len(band_list) * (_gdal.GetDataTypeSize(buf_type) / 8))
            if version_info >= (3,0,0):
                buf_obj_ar = [ None ]
                exec("buf_obj_ar[0] = b' ' * nRequiredSize")
                buf_obj = buf_obj_ar[0]
            else:
                buf_obj = ' ' * nRequiredSize
        return _gdal.Dataset_BeginAsyncReader(self, xoff, yoff, xsize, ysize, buf_obj, buf_xsize, buf_ysize, buf_type, band_list,  0, 0, 0, options)