python 教程 第十章、 输入/输出

第十章、 输入/输出
1)    文件

poem = '''Programming is fun use Python!'''

f = file('poem.txt', 'w') # open for 'w'riting

f.write(poem) # write text to file

f.close() # close the file

可以使用help(file)来了解详情。

2)    储存器
pickle在文件中储存Python对象，cPickle(C语言,更快)

import cPickle as p

shoplistfile = 'shoplist.data'

shoplist = ['apple', 'mango', 'carrot', 'donggua']

f = file(shoplistfile, 'w')

p.dump(shoplist, f) # dump the object to a file

f.close() 

#使用pickle

import pickle

object = someClass()

file   = open(filename, 'wb')     # Create external file

pickle.dump(object, file)         # Save object in file

import pickle

file   = open(filename, 'rb')

object = pickle.load(file)        # Fetch it back later 

#使用shelve

import shelve

object = someClass()

dbase  = shelve.open('filename')

dbase['key'] = object             # Save under key

import shelve

dbase  = shelve.open('filename')

object = dbase['key']             # Fetch it back later