Python File next()用法及代碼示例

描述

Python文件方法next()當文件用作迭代器時使用，通常在循環中，重複調用 next() 方法。此方法返回下一個輸入行，或在命中 EOF 時引發 StopIteration。

將 next() 方法與其他文件方法(如 readline())結合使用是行不通的。但是，將文件重新定位到絕對位置的 usingseek() 將刷新 read-ahead 緩衝區。

用法

以下是語法next()方法≫

fileObject.next(); 

參數

• NA

返回值

此方法返回下一個輸入行。

示例

下麵的例子展示了 next() 方法的用法。

This is 1st line
This is 2nd line
This is 3rd line
This is 4th line
This is 5th line

#!/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()

當我們運行上麵的程序時，它會產生以下結果——

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