python编程中对文件和存储器的读写示例

1.文件的写入和读取

#!/usr/bin/python
# -*- coding: utf-8 -*-
# filename: using_file.py
# 文件是创建和读取
s = ””’我们都是木头人,
不许说话不许动!”’
# 创建一个文件,并且写入字符
f = file(‘test_file.txt’, ‘w’)
f.write(s)
f.close()
# 读取文件,逐行打印
f = file(‘test_file.txt’)
while true:
line = f.readline()
# 如果line长度为0,说明文件已经读完了
if len(line) == 0:
break
# 默认的换行符也读出来了,所以用逗号取代print函数的换行符
print line,
f.close()

执行结果:

我们都是木头人,
不许说话不许动!

2.存储器的写入和读取

#!/usr/bin/python
# -*- coding: utf-8 -*-
# filename using_pickle.py
# 使用存储器
#加载存储器模块,as后面是别名
#import pickle as p
#书上说cpickle比pickle快很多
import cpickle as p
listpickle = [1, 2, 2, 3]
picklefile = ‘picklefile.data’
f = file(picklefile, ‘w’)
# 写如数据
p.dump(listpickle, f)
f.close()
del listpickle
f = file(picklefile)
# 读取数据
storedlist = p.load(f)
print storedlist
f.close()

执行结果:

[1, 2, 2, 3]

再来看一个使用cpickle储存器存储对象的例子

#!/usr/bin/python
#filename:pickling.py
import cpickle as p
shoplistfile = ‘shoplist.data’
shoplist = [‘apple’, ‘mango’, ‘carrot’]
f = file(shoplistfile, ‘w’)
p.dump(shoplist, f)
f.close()
del shoplist
f = file(shoplistfile)
storedlist = p.load(f)
print storedlist

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