warplib.py 文件源码

def parse_srs(t_srs, src_ds_list=None):
    """Parse arbitrary input t_srs

    Parameters
    ----------
    t_srs : str or gdal.Dataset or filename
        Arbitrary input t_srs 
    src_ds_list : list of gdal.Dataset objects, optional
        Needed if specifying 'first' or 'last'

    Returns
    -------
    t_srs : osr.SpatialReference() object
        Output spatial reference system
    """
    if t_srs is None and src_ds_list is None:
        print("Input t_srs and src_ds_list are both None")
    else:
        if t_srs is None:
            t_srs = 'first'
        if t_srs == 'first' and src_ds_list is not None:
            t_srs = geolib.get_ds_srs(src_ds_list[0])
        elif t_srs == 'last' and src_ds_list is not None:
            t_srs = geolib.get_ds_srs(src_ds_list[-1])
        #elif t_srs == 'source':
        #    t_srs = None 
        elif isinstance(t_srs, osr.SpatialReference): 
            pass
        elif isinstance(t_srs, gdal.Dataset):
            t_srs = geolib.get_ds_srs(t_srs)
        elif isinstance(t_srs, str) and os.path.exists(t_srs): 
            t_srs = geolib.get_ds_srs(gdal.Open(t_srs))
        elif isinstance(t_srs, str):
            temp = osr.SpatialReference()
            if 'EPSG' in t_srs.upper():
                epsgcode = int(t_srs.split(':')[-1])
                temp.ImportFromEPSG(epsgcode)
            elif 'proj' in t_srs:
                temp.ImportFromProj4(t_srs)
            else:
                #Assume the user knows what they are doing
                temp.ImportFromWkt(t_srs)
            t_srs = temp
        else:
            t_srs = None
    return t_srs