将列表转储到pickle文件中并稍后检索[关闭]

Posted 2023-02-16

【中文标题】将列表转储到pickle文件中并稍后检索[关闭]

【英文标题】：Dump a list in a pickle file and retrieve it back later [closed]

【发布时间】：2014-10-17 07:51:52

【问题描述】：

我正在尝试保存一个字符串列表，以便以后可以访问它。如何使用泡菜来实现？一个说明性的例子可能会有所帮助。

【问题讨论】：

你看过文档了吗？ docs.python.org/3/library/pickle.html#examples

如果您不关心速度和安全性，最简单的方法是repr 和eval。

列表包含什么？

列表只包含字符串

那么json 是更轻量级的选项。

【参考方案1】：

Pickling 将序列化您的列表（将其转换为唯一的字节字符串），因此您可以将其保存到磁盘。您还可以使用 pickle 检索您的原始列表，从保存的文件中加载。

所以，首先建立一个列表，然后使用pickle.dump 将其发送到一个文件...

Python 3.4.1 (default, May 21 2014, 12:39:51) 
[GCC 4.2.1 Compatible Apple LLVM 5.0 (clang-500.2.79)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> mylist = ['I wish to complain about this parrot what I purchased not half an hour ago from this very boutique.', "Oh yes, the, uh, the Norwegian Blue...What's,uh...What's wrong with it?", "I'll tell you what's wrong with it, my lad. 'E's dead, that's what's wrong with it!", "No, no, 'e's uh,...he's resting."]
>>> 
>>> import pickle
>>> 
>>> with open('parrot.pkl', 'wb') as f:
...   pickle.dump(mylist, f)
... 
>>> 

然后退出并稍后再回来...并使用pickle.load打开...

Python 3.4.1 (default, May 21 2014, 12:39:51) 
[GCC 4.2.1 Compatible Apple LLVM 5.0 (clang-500.2.79)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> import pickle
>>> with open('parrot.pkl', 'rb') as f:
...   mynewlist = pickle.load(f)
... 
>>> mynewlist
['I wish to complain about this parrot what I purchased not half an hour ago from this very boutique.', "Oh yes, the, uh, the Norwegian Blue...What's,uh...What's wrong with it?", "I'll tell you what's wrong with it, my lad. 'E's dead, that's what's wrong with it!", "No, no, 'e's uh,...he's resting."]
>>>

【讨论】：

如果列表对您的内存来说太大了怎么办，所以您不想一次将整个列表读入内存，而只想一次读取列表的一部分。是否可以通过pickle仅将部分列表读取到内存中？

@Watt：如果它被腌制为一个列表，那么不会。如果列表被转换为可以大步阅读的东西，那么是的。