-
Notifications
You must be signed in to change notification settings - Fork 419
Expand file tree
/
Copy pathpython.serializable.html
More file actions
148 lines (112 loc) · 7.81 KB
/
Copy pathpython.serializable.html
File metadata and controls
148 lines (112 loc) · 7.81 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>1.9. 序列化</title><link rel="stylesheet" type="text/css" href="../docbook.css" /><meta name="generator" content="DocBook XSL Stylesheets Vsnapshot" /><meta name="keywords" content="php,pear,pecl,phar, python, , " /><link rel="home" href="../index.html" title="Netkiller Python 手札" /><link rel="up" href="index.html" title="第 1 章 Python 入门" /><link rel="prev" href="python.datastruct.html" title="1.8. 数据结构" /><link rel="next" href="class.html" title="1.10. Class" /></head><body><a xmlns="" href="//www.netkiller.cn/">Home</a> | <a xmlns="" href="//netkiller.github.io/">简体中文</a> | <a xmlns="" href="http://netkiller.sourceforge.net/">繁体中文</a> | <a xmlns="" href="/journal/index.html">杂文</a>
| <a xmlns="" href="https://github.com/netkiller">Github</a> | <a xmlns="" href="https://zhuanlan.zhihu.com/netkiller">知乎专栏</a> | <a xmlns="" href="https://www.facebook.com/bg7nyt">Facebook</a> | <a xmlns="" href="http://cn.linkedin.com/in/netkiller/">Linkedin</a> | <a xmlns="" href="https://www.youtube.com/user/bg7nyt/videos">Youtube</a> | <a xmlns="" href="//www.netkiller.cn/home/donations.html">打赏(Donations)</a> | <a xmlns="" href="//www.netkiller.cn/home/about.html">About</a><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">1.9. 序列化 </th></tr><tr><td width="20%" align="left"><a accesskey="p" href="python.datastruct.html">上一页</a> </td><th width="60%" align="center">第 1 章 Python 入门</th><td width="20%" align="right"> <a accesskey="n" href="class.html">下一页</a></td></tr></table><hr /></div><table xmlns=""><tr><td><iframe src="//ghbtns.com/github-btn.html?user=netkiller&repo=netkiller.github.io&type=watch&count=true&size=large" height="30" width="170" frameborder="0" scrolling="0" style="width:170px; height: 30px;" allowTransparency="true"></iframe></td><td><iframe src="//ghbtns.com/github-btn.html?user=netkiller&repo=netkiller.github.io&type=fork&count=true&size=large" height="30" width="170" frameborder="0" scrolling="0" style="width:170px; height: 30px;" allowTransparency="true"></iframe></td><td><iframe src="//ghbtns.com/github-btn.html?user=netkiller&type=follow&count=true&size=large" height="30" width="240" frameborder="0" scrolling="0" style="width:240px; height: 30px;" allowTransparency="true"></iframe></td><td></td><td><a href="https://zhuanlan.zhihu.com/netkiller"><img src="/images/logo/zhihu-card-default.svg" height="25" /></a></td><td valign="middle"><a href="https://zhuanlan.zhihu.com/netkiller">知乎专栏</a></td><td></td><td></td><td></td><td></td></tr></table><div class="section"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="python.serializable"></a>1.9. 序列化 </h2></div></div></div>
<div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="id892"></a>1.9.1. struct C 语言结构体序列化</h3></div></div></div>
<div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="id889"></a>1.9.1.1. 端序</h4></div></div></div>
<p>不同的场景使用不同的端序方案，不同的方案是不同历史时期，计算机厂商指定标准。</p>
<pre class="programlisting">
import struct
print("原生",struct.pack('@h', 1023))
print("标准",struct.pack('=h', 1023))
print("小端",struct.pack('<h', 1023))
print("大端",struct.pack('>h', 1023))
print("网络",struct.pack('!h', 1023))
</pre>
<p>输出结果</p>
<pre class="screen">
原生 b'\xff\x03'
标准 b'\xff\x03'
小端 b'\xff\x03'
大端 b'\x03\xff'
网络 b'\x03\xff'
</pre>
</div>
<div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="id890"></a>1.9.1.2. Struct 类</h4></div></div></div>
<p></p>
<pre class="programlisting">
import struct
format = '!HHH'
audio = struct.Struct(format)
print(f"{audio.size}")
encode = audio.pack(2,2000,65535)
print(f"{len(encode)}: {encode}")
</pre>
<p>输出结果</p>
<pre class="screen">
6
6: b'\x00\x02\x07\xd0\xff\xff'
</pre>
</div>
<div class="section"><div class="titlepage"><div><div><h4 class="title"><a id="id891"></a>1.9.1.3. char 与 signed char / unsigned char 的区别</h4></div></div></div>
<p>char 存储的是字符，signed char / unsigned char 存储的是有符号和无符号整数，相当于 int(1) 长度，当我们需要标准大小为1的时候可以使用 signed char / unsigned char </p>
<pre class="programlisting">
import struct
data = struct.pack('c', b"A")
print(f"{len(data)},{data}") # 输出 1 字节
c = struct.unpack('c', data)
print(c)
# 打包一个 1 字节无符号整数 0～255
data = struct.pack('!B', 120)
print(f"{len(data)},{data}") # 输出 1 字节
num = struct.unpack('!B', data)
print(num)
</pre>
<p>输出结果</p>
<pre class="screen">
1,b'A'
(b'A',)
1,b'x'
(120,)
</pre>
</div>
</div>
<div class="section"><div class="titlepage"><div><div><h3 class="title"><a id="python.shelve"></a>1.9.2. shelve(序列化)</h3></div></div></div>
<pre class="programlisting">
import shelve
with shelve.open("/var/tmp/test") as db:
db["hello"] = "helloworld"
with shelve.open("/var/tmp/test") as db:
for k, v in db.items():
print(k, ":", v)
</pre>
<pre class="programlisting">
import shelve, json
data = json.loads(json.dumps({"800": "AAAA", "900": "BBBB", "1000": "CCCC"}))
print(data, type(data))
with shelve.open("/var/tmp/test", "n") as db:
for k, v in data.items():
db[k] = v
with shelve.open("/var/tmp/test") as db:
for k, v in db.items():
print(k, ":", v)
</pre>
</div>
</div><script xmlns="" type="text/javascript" id="clustrmaps" src="//cdn.clustrmaps.com/map_v2.js?u=r5HG&d=9mi5r_kkDC8uxG8HuY3p4-2qgeeVypAK9vMD-2P6BYM"></script><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="python.datastruct.html">上一页</a> </td><td width="20%" align="center"><a accesskey="u" href="index.html">上一级</a></td><td width="40%" align="right"> <a accesskey="n" href="class.html">下一页</a></td></tr><tr><td width="40%" align="left" valign="top">1.8. 数据结构 </td><td width="20%" align="center"><a accesskey="h" href="../index.html">起始页</a></td><td width="40%" align="right" valign="top"> 1.10. Class</td></tr></table></div><script xmlns="">
(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
})(window,document,'script','//www.google-analytics.com/analytics.js','ga');
ga('create', 'UA-11694057-1', 'auto');
ga('send', 'pageview');
</script><script xmlns="" async="async">
var _hmt = _hmt || [];
(function() {
var hm = document.createElement("script");
hm.src = "https://hm.baidu.com/hm.js?93967759a51cda79e49bf4e34d0b0f2c";
var s = document.getElementsByTagName("script")[0];
s.parentNode.insertBefore(hm, s);
})();
</script><script xmlns="" async="async">
(function(){
var bp = document.createElement('script');
var curProtocol = window.location.protocol.split(':')[0];
if (curProtocol === 'https') {
bp.src = 'https://zz.bdstatic.com/linksubmit/push.js';
}
else {
bp.src = 'http://push.zhanzhang.baidu.com/push.js';
}
var s = document.getElementsByTagName("script")[0];
s.parentNode.insertBefore(bp, s);
})();
</script></body></html>