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