next()方法当一个文件被用作迭代器，典型例子是在一个循环中被使用，next()方法被反复调用。此方法返回下一个输入行，或引发StopIteration异常EOF时被命中。
与其它文件的方法，如ReadLine()相结合next()方法工作不正常。然而，usingseek()将文件重新定位到一个绝对位置将刷新预读缓冲器。
语法
以下是next()方法的语法：
fileObject.next();
参数
返回值
此方法返回下一个输入行。
例子
下面的示例演示next()方法的使用。
#!/usr/bin/python
# Open a file
fo = open("foo.txt", "rw+")
print "Name of the file: ", fo.name
# Assuming file has following 5 lines
# This is 1st line
# This is 2nd line
# This is 3rd line
# This is 4th line
# This is 5th line
for index in range(5):
line = fo.next()
print "Line No %d - %s" % (index, line)
# Close opend file
fo.close()
当我们运行上面的程序，它会产生以下结果：
Name of the file: foo.txt Line No 0 - This is 1st line Line No 1 - This is 2nd line Line No 2 - This is 3rd line Line No 3 - This is 4th line Line No 4 - This is 5th line
原文：http://www.jb51.net/article/66628.htm