简明Python教程读书笔记-9 文件操作

1. 文件读写

Python中通过file类实现对文件的操作，如f = file('test.txt', 'w')表示以写方式打开文件test.txt，如果不指定打开方式，默认为读方式打开文件。文件的打开方式包括读、写和追加

2. 对象的持久化存储

在文件中存储对象，可以通过文件恢复对象的值。通过pickle和cPickle类实现（后者通过C编写，速度较快）

import cPickle as p
shoplistfile = 'shoplist.data'
# the name of the file where we will store the object
shoplist = ['apple', 'mango', 'carrot']
# Write to the file
f = open(shoplistfile, 'wb')
p.dump(shoplist, f) # dump the object to a file
f.close()
del shoplist # remove the shoplist
# Read back from the storage
f = open(shoplistfile, 'rb')
storedlist = p.load(f)
print(storedlist)

Python3版本中，文件打开方式必须为wb和rb