写代码写错了顺序，所以想办法把x,y坐标调换回来

def change_ptsxy(fileName):    fp = open(fileName)    i = 0    file_data = ""    for line in fp.xreadlines():        # print line.strip("\n")        TT = line.strip("\n")        if i > 2 and i < 71:            # print TT            TT_temp = TT.split(" ")            x = int(float(TT_temp[0]))            y = int(float(TT_temp[1].strip("\r")))            old_str=str(x)+" "+str(y)            new_str=str(y)+" "+str(x)            # print(new_str)            line = line.replace(old_str, new_str)            file_data += line            # print(file_data)        else:            file_data += line        i += 1    fp = open(fileName, 'w+')