python逐行读取文件中内容

文件中内容说明：

文件中每行数据格式为
$,351.54,40.1914438,116.0638454,131.35,0.021,-0.0058,-0.0265,-0.0200,05,*2E

现在要拿到数据中的经纬度，即以逗号分割的第三个和第四个数据

代码如下：

#!/usr/bin/python
# -*- coding: UTF-8 -*-

fo = open("A.lpx","rw+")
print "file name : ", fo.name

line = fo.readline()
while line:
	gpsdata = line.split(',')
	print "%s,%s" %(gpsdata[2],gpsdata[3])
	line = fo.readline()

fo.close

解析结果：

40.1917166,116.0636262
40.1917167,116.0636239
40.1917167,116.0636215
40.1917164,116.0636192
40.1917163,116.0636169
40.1917162,116.0636145
40.1917163,116.0636122
40.1917161,116.0636099
40.1917156,116.0636076
40.1917157,116.0636053
40.1917156,116.0636029
40.1917153,116.0636006
40.1917148,116.0635984
40.1917148,116.0635960
40.1917147,116.0635937
40.1917143,116.0635914
40.1917139,116.0635891