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