[Python小白学习笔记第1课：Python简介（2024版）](__GHOST_URL__/post/43/)

Python是跨平台的，它可以运行在Windows、macOS和各种Linux/Unix系统上。

想学Python，首先得把Python安装到电脑里。由于使用Windows的人数最多，下面就以Windows 11为例讲解Python的安装。

## 下载安装包

Python官网：[https://www.python.org/downloads/](https://www.python.org/downloads/)

官网下载慢的话，可到这里下载：[https://gaga.lanzoum.com/b033e9rbi](https://gaga.lanzoum.com/b033e9rbi) 密码:1234

## 安装Python解释器

在Windows上安装Python和安装普通软件一样，找到下载好的安装文件：python-3.12.1-amd64.exe，双击启动安装向导。

勾选“Use admin privileges when installing py.exe(安装py.exe时使用管理员权限运行)”和“Add python.exe to PATH(将Python解释器路径添加到系统环境变量中)”，接着点击“Install Now”。

最后如果有出现“Disable path length limit(禁用路径长度限制)”的选项，点击进行解除限制（取消路径长度最大260个字符限制），没有的话直接关闭即可。

## 验证Python安装

打开命令提示符窗口，输入`python`后回车，若出现Python相关版本等信息，并且输入光标变为`>>>`，表示已经进入Python交互式环境中，说明Python安装成功。

最后，输入`exit()`或`quit()`（也可使用Ctrl+Z后回车）即可退出Python交互式环境，回到Windows命令行模式。

## IPython

Python默认的交互式环境（CPython解释器）用户体验并不怎么好，可用IPython来替换掉它，因为IPython提供了更为强大的编辑和交互功能。

安装IPython：`pip install ipython`（如果下载安装过程觉得慢的话，可以参考[修改pip镜像源加快模块下载速度](__GHOST_URL__/post/51/)）。

高级功能：

- Tab键自动补全命令
- ?：内省、命名空间搜索
- !：执行系统命令
- 魔术命令：以%开始的命令

- %run：执行文件代码
- %paste：执行剪贴板代码
- %timeit：评估运行时间
- %pdb：自动调试

- 快捷键

- Ctrl + A：移动到行首
- Ctrl + E：移动到行尾
- Ctrl + F：向前移动一个字符
- Ctrl + B：向后移动一个字符
- Ctrl + D：删除当前字符（如果光标位于行首，则退出IPython）
- Ctrl + K：删除从光标到行尾的内容
- Ctrl + U：删除从行首到光标的内容
- Ctrl + R：反向搜索历史命令
- Ctrl + C：中断当前执行的命令

## IDE集成开发环境

IDE英文是Integrated Development Environment，集成开发环境的意思。其实，在安装好Python之后，会自带一个叫做IDLE的集成开发环境。但是，Python自带的IDLE比较简单，一般不用它。

集成开发环境本质上是对Python解释器python.exe的封装，可以说集成开发环境IDE，只是Python解释器的一个外挂而已，只是为了让程序员更加方便编程，减少出错率，尤其是拼写错误。

常用集成开发环境如下：

- IDLE
- VS Code（推荐）
- PyCharm（推荐）
- Jupyter

PyCharm快捷键：

- Ctrl+D：复制当前行到下一行
- Ctrl+/：注释
- Ctrl+Alt+L：快速格式化代码
- Alt+R：快速运行程序，需自定义
- Ctrl+H：查看类层级关系
- Ctrl+F：查找，Ctrl+R：替换

## 第一个Python程序

搭建完Python运行环境，就可以编写第一个Python程序了。

### 交互模式

打开命令提示符窗口，输入`python`后回车，进入到Python交互式环境： C:\Users\abc\Desktop>python Python 3.12.1 ... on win32 Type "help" ... information. >>> print("hello, world") hello, world >>> quit()

C:\Users\abc\Desktop>

第一个Python程序就这么完成了，是不是超级简单！唯一缺憾是代码没有保存下来，下次运行时还要再输一遍代码。

### 命令行模式

打开记事本，写入`print("hello, world")`后保存为hello.py，接着打开命令提示符窗口： C:\Users\abc\Desktop>python hello.py hello, world

C:\Users\abc\Desktop>

用记事本写好Python程序，保存后缀为.py的文件，就可以用python命令直接运行这个程序了。

## 在线体验Python

在线Python解释器：[https://www.tutorialspoint.com/online_python_compiler.php](https://www.tutorialspoint.com/online_python_compiler.php)

[Python小白学习笔记第3课：Python编码规范（2024版）](__GHOST_URL__/post/49/)


Python小白学习笔记第2课：Python运行环境搭建（2024版）

## JS逆向

出于对数据安全的考虑，一些网站/APP通常会对数据接口做加密处理。而分析这些接口的加密算法并实现模拟调用的过程就叫做「逆向」。

## 标准算法解密

1. 确定JS是否存在混淆或者加密（eval）
2. 定位解密位置

### 搜索decrypt

举例，目标网站地址如下： [password pass='5566@Vip' desc='输入密码可见'] 福建省公共资源交易电子公共服务平台：[https://ggzyfw.fujian.gov.cn/business/list](https://ggzyfw.fujian.gov.cn/business/list)

数据接口解密：

const cryptoJS = require('crypto-js') function b(t) { var e = cryptoJS.enc.Utf8.parse('EB444973714E4A40876CE66BE45D5930'), n = cryptoJS.enc.Utf8.parse('B5A8904209931867'), a = cryptoJS.AES.decrypt(t, e, { iv: n, mode: cryptoJS.mode.CBC, padding: cryptoJS.pad.Pkcs7, }) return a.toString(cryptoJS.enc.Utf8) } const data = '密文' console.log(b(data))

[/ppblock]

### 搜索关键字

例如搜索：encrypt_data，示例网站地址如下： [ppblock ex="请输入密码"] 企名片-科技创新服务平台：[https://www.qimingpian.com/finosda/project/ainvestment](https://www.qimingpian.com/finosda/project/ainvestment)function decode(t) { var f = '/[\t\n\f\r ]/g' var l = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/' var e = (t = String(t).replace(f, '')).length e % 4 == 0 && (e = (t = t.replace(/==?$/, '')).length), (e % 4 == 1 || /[^+a-zA-Z0-9/]/.test(t)) && u('Invalid character: the string to be decoded is not correctly encoded.') for (var n, r, i = 0, o = '', a = -1; ++a < e; ) (r = l.indexOf(t.charAt(a))), (n = i % 4 ? 64 * n + r : r), i++ % 4 && (o += String.fromCharCode(255 & (n >> ((-2 * i) & 6)))) return o }

function o(e, t, i, n, a, o) {
var s, c, r, l, d, u, h, p, f, m, v, g, y, b, C = new Array(16843776,0,65536,16843780,16842756,66564,4,65536,1024,16843776,16843780,1024,16778244,16842756,16777216,4,1028,16778240,16778240,66560,66560,16842752,16842752,16778244,65540,16777220,16777220,65540,0,1028,66564,16777216,65536,16843780,4,16842752,16843776,16777216,16777216,1024,16842756,65536,66560,16777220,1024,4,16778244,66564,16843780,65540,16842752,16778244,16777220,1028,66564,16843776,1028,16778240,16778240,0,65540,66560,0,16842756), _ = new Array(-2146402272,-2147450880,32768,1081376,1048576,32,-2146435040,-2147450848,-2147483616,-2146402272,-2146402304,-2147483648,-2147450880,1048576,32,-2146435040,1081344,1048608,-2147450848,0,-2147483648,32768,1081376,-2146435072,1048608,-2147483616,0,1081344,32800,-2146402304,-2146435072,32800,0,1081376,-2146435040,1048576,-2147450848,-2146435072,-2146402304,32768,-2146435072,-2147450880,32,-2146402272,1081376,32,32768,-2147483648,32800,-2146402304,1048576,-2147483616,1048608,-2147450848,-2147483616,1048608,1081344,0,-2147450880,32800,-2147483648,-2146435040,-2146402272,1081344), w = new Array(520,134349312,0,134348808,134218240,0,131592,134218240,131080,134217736,134217736,131072,134349320,131080,134348800,520,134217728,8,134349312,512,131584,134348800,134348808,131592,134218248,131584,131072,134218248,8,134349320,512,134217728,134349312,134217728,131080,520,131072,134349312,134218240,0,512,131080,134349320,134218240,134217736,512,0,134348808,134218248,131072,134217728,134349320,8,131592,131584,134217736,134348800,134218248,520,134348800,131592,8,134348808,131584), k = new Array(8396801,8321,8321,128,8396928,8388737,8388609,8193,0,8396800,8396800,8396929,129,0,8388736,8388609,1,8192,8388608,8396801,128,8388608,8193,8320,8388737,1,8320,8388736,8192,8396928,8396929,129,8388736,8388609,8396800,8396929,129,0,0,8396800,8320,8388736,8388737,1,8396801,8321,8321,128,8396929,129,1,8192,8388609,8193,8396928,8388737,8193,8320,8388608,8396801,128,8388608,8192,8396928), x = new Array(256,34078976,34078720,1107296512,524288,256,1073741824,34078720,1074266368,524288,33554688,1074266368,1107296512,1107820544,524544,1073741824,33554432,1074266112,1074266112,0,1073742080,1107820800,1107820800,33554688,1107820544,1073742080,0,1107296256,34078976,33554432,1107296256,524544,524288,1107296512,256,33554432,1073741824,34078720,1107296512,1074266368,33554688,1073741824,1107820544,34078976,1074266368,256,33554432,1107820544,1107820800,524544,1107296256,1107820800,34078720,0,1074266112,1107296256,524544,33554688,1073742080,524288,0,1074266112,34078976,1073742080), T = new Array(536870928,541065216,16384,541081616,541065216,16,541081616,4194304,536887296,4210704,4194304,536870928,4194320,536887296,536870912,16400,0,4194320,536887312,16384,4210688,536887312,16,541065232,541065232,0,4210704,541081600,16400,4210688,541081600,536870912,536887296,16,541065232,4210688,541081616,4194304,16400,536870928,4194304,536887296,536870912,16400,536870928,541081616,4210688,541065216,4210704,541081600,0,541065232,16,16384,541065216,4210704,16384,4194320,536887312,0,541081600,536870912,4194320,536887312), A = new Array(2097152,69206018,67110914,0,2048,67110914,2099202,69208064,69208066,2097152,0,67108866,2,67108864,69206018,2050,67110912,2099202,2097154,67110912,67108866,69206016,69208064,2097154,69206016,2048,2050,69208066,2099200,2,67108864,2099200,67108864,2099200,2097152,67110914,67110914,69206018,69206018,2,2097154,67108864,67110912,2097152,69208064,2050,2099202,69208064,2050,67108866,69208066,69206016,2099200,0,2,69208066,0,2099202,69206016,2048,67108866,67110912,2048,2097154), N = new Array(268439616,4096,262144,268701760,268435456,268439616,64,268435456,262208,268697600,268701760,266240,268701696,266304,4096,64,268697600,268435520,268439552,4160,266240,262208,268697664,268701696,4160,0,0,268697664,268435520,268439552,266304,262144,266304,262144,268701696,4096,64,268697664,4096,266304,268439552,64,268435520,268697600,268697664,268435456,262144,268439616,0,268701760,262208,268435520,268697600,268439552,268439616,0,268701760,266240,266240,4160,4160,262208,268435456,268701696), $ = function(e) {
for (var t, i, n, a = new Array(0,4,536870912,536870916,65536,65540,536936448,536936452,512,516,536871424,536871428,66048,66052,536936960,536936964), o = new Array(0,1,1048576,1048577,67108864,67108865,68157440,68157441,256,257,1048832,1048833,67109120,67109121,68157696,68157697), s = new Array(0,8,2048,2056,16777216,16777224,16779264,16779272,0,8,2048,2056,16777216,16777224,16779264,16779272), c = new Array(0,2097152,134217728,136314880,8192,2105344,134225920,136323072,131072,2228224,134348800,136445952,139264,2236416,134356992,136454144), r = new Array(0,262144,16,262160,0,262144,16,262160,4096,266240,4112,266256,4096,266240,4112,266256), l = new Array(0,1024,32,1056,0,1024,32,1056,33554432,33555456,33554464,33555488,33554432,33555456,33554464,33555488), d = new Array(0,268435456,524288,268959744,2,268435458,524290,268959746,0,268435456,524288,268959744,2,268435458,524290,268959746), u = new Array(0,65536,2048,67584,536870912,536936448,536872960,536938496,131072,196608,133120,198656,537001984,537067520,537004032,537069568), h = new Array(0,262144,0,262144,2,262146,2,262146,33554432,33816576,33554432,33816576,33554434,33816578,33554434,33816578), p = new Array(0,268435456,8,268435464,0,268435456,8,268435464,1024,268436480,1032,268436488,1024,268436480,1032,268436488), f = new Array(0,32,0,32,1048576,1048608,1048576,1048608,8192,8224,8192,8224,1056768,1056800,1056768,1056800), m = new Array(0,16777216,512,16777728,2097152,18874368,2097664,18874880,67108864,83886080,67109376,83886592,69206016,85983232,69206528,85983744), v = new Array(0,4096,134217728,134221824,524288,528384,134742016,134746112,16,4112,134217744,134221840,524304,528400,134742032,134746128), g = new Array(0,4,256,260,0,4,256,260,1,5,257,261,1,5,257,261), y = e.length > 8 ? 3 : 1, b = new Array(32 * y), C = new Array(0,0,1,1,1,1,1,1,0,1,1,1,1,1,1,0), _ = 0, w = 0, k = 0; k < y; k++) {
var x = e.charCodeAt(*++) << 24 | e.charCodeAt(*++) << 16 | e.charCodeAt(*++) << 8 | e.charCodeAt(*++)
, T = e.charCodeAt(*++) << 24 | e.charCodeAt(*++) << 16 | e.charCodeAt(*++) << 8 | e.charCodeAt(*++);
x ^= (n = 252645135 & (x >>> 4 ^ T)) << 4,
x ^= n = 65535 & ((T ^= n) >>> -16 ^ x),
x ^= (n = 858993459 & (x >>> 2 ^ (T ^= n << -16))) << 2,
x ^= n = 65535 & ((T ^= n) >>> -16 ^ x),
x ^= (n = 1431655765 & (x >>> 1 ^ (T ^= n << -16))) << 1,
x ^= n = 16711935 & ((T ^= n) >>> 8 ^ x),
n = (x ^= (n = 1431655765 & (x >>> 1 ^ (T ^= n << 8))) << 1) << 8 | (T ^= n) >>> 20 & 240,
x = T << 24 | T << 8 & 16711680 | T >>> 8 & 65280 | T >>> 24 & 240,
T = n;
for (var A = 0; A < C.length; A++)
C[A] ? (x = x << 2 | x >>> 26,
T = T << 2 | T >>> 26) : (x = x << 1 | x >>> 27,
T = T << 1 | T >>> 27),
T &= -15,
t = a[(x &= -15) >>> 28] | o[x >>> 24 & 15] | s[x >>> 20 & 15] | c[x >>> 16 & 15] | r[x >>> 12 & 15] | l[x >>> 8 & 15] | d[x >>> 4 & 15],
i = u[T >>> 28] | h[T >>> 24 & 15] | p[T >>> 20 & 15] | f[T >>> 16 & 15] | m[T >>> 12 & 15] | v[T >>> 8 & 15] | g[T >>> 4 & 15],
n = 65535 & (i >>> 16 ^ t),
b[w++] = t ^ n,
b[w++] = i ^ n << 16
}
return b
}(e), L = 0, S = t.length, z = 0, I = 32 == $.length ? 3 : 9;
p = 3 == I ? i ? new Array(0,32,2) : new Array(30,-2,-2) : i ? new Array(0,32,2,62,30,-2,64,96,2) : new Array(94,62,-2,32,64,2,30,-2,-2),
2 == o ? t += "        " : 1 == o ? i && (r = 8 - S % 8,
t += String.fromCharCode(r, r, r, r, r, r, r, r),
8 === r && (S += 8)) : o || (t += "\0\0\0\0\0\0\0\0");
var B = ""
, F = "";
for (1 == n && (f = a.charCodeAt(L++) << 24 | a.charCodeAt(L++) << 16 | a.charCodeAt(L++) << 8 | a.charCodeAt(L++),
v = a.charCodeAt(L++) << 24 | a.charCodeAt(L++) << 16 | a.charCodeAt(L++) << 8 | a.charCodeAt(L++),
L = 0); L < S; ) {
for (u = t.charCodeAt(L++) << 24 | t.charCodeAt(L++) << 16 | t.charCodeAt(L++) << 8 | t.charCodeAt(L++),
h = t.charCodeAt(L++) << 24 | t.charCodeAt(L++) << 16 | t.charCodeAt(L++) << 8 | t.charCodeAt(L++),
1 == n && (i ? (u ^= f,
h ^= v) : (m = f,
g = v,
f = u,
v = h)),
u ^= (r = 252645135 & (u >>> 4 ^ h)) << 4,
u ^= (r = 65535 & (u >>> 16 ^ (h ^= r))) << 16,
u ^= r = 858993459 & ((h ^= r) >>> 2 ^ u),
u ^= r = 16711935 & ((h ^= r << 2) >>> 8 ^ u),
u = (u ^= (r = 1431655765 & (u >>> 1 ^ (h ^= r << 8))) << 1) << 1 | u >>> 31,
h = (h ^= r) << 1 | h >>> 31,
c = 0; c < I; c += 3) {
for (y = p[c + 1],
b = p[c + 2],
s = p[c]; s != y; s += b)
l = h ^ $[s],
d = (h >>> 4 | h << 28) ^ $[s + 1],
r = u,
u = h,
h = r ^ (_[l >>> 24 & 63] | k[l >>> 16 & 63] | T[l >>> 8 & 63] | N[63 & l] | C[d >>> 24 & 63] | w[d >>> 16 & 63] | x[d >>> 8 & 63] | A[63 & d]);
r = u,
u = h,
h = r
}
h = h >>> 1 | h << 31,
h ^= r = 1431655765 & ((u = u >>> 1 | u << 31) >>> 1 ^ h),
h ^= (r = 16711935 & (h >>> 8 ^ (u ^= r << 1))) << 8,
h ^= (r = 858993459 & (h >>> 2 ^ (u ^= r))) << 2,
h ^= r = 65535 & ((u ^= r) >>> 16 ^ h),
h ^= r = 252645135 & ((u ^= r << 16) >>> 4 ^ h),
u ^= r << 4,
1 == n && (i ? (f = u,
v = h) : (u ^= m,
h ^= g)),
F += String.fromCharCode(u >>> 24, u >>> 16 & 255, u >>> 8 & 255, 255 & u, h >>> 24, h >>> 16 & 255, h >>> 8 & 255, 255 & h),
512 == (z += 8) && (B += F,
F = "",
z = 0)
}
if (B = (B += F).replace(/\0*$/g, ""),
!i) {
if (1 === o) {
var j = 0;
(S = B.length) && (j = B.charCodeAt(S - 1)),
j <= 8 && (B = B.substring(0, S - j))
}
B = decodeURIComponent(escape(B))
}
return B
}

function s(e) {
return JSON.parse(o('5e5062e82f15fe4ca9d24bc5', decode(e), 0, 0, '012345677890123', 1))
}

const data = '密文'
console.log(s(data))

[/ppblock]

### 搜索JSON.parse(

示例网站地址如下： [ppblock ex="请输入密码"] 烯牛数据：[https://www.xiniudata.com/industry/newest?from=data](https://www.xiniudata.com/industry/newest?from=data)function d1(t) { var e, r, n, o, i, a, c = '', u = 0 var _keyStr = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=' for (t = t.replace(/[^A-Za-z0-9\+\/\=]/g, ''); u < t.length; ) (e = (_keyStr.indexOf(t.charAt(u++)) << 2) | ((o = _keyStr.indexOf(t.charAt(u++))) >> 4)), (r = ((15 & o) << 4) | ((i = _keyStr.indexOf(t.charAt(u++))) >> 2)), (n = ((3 & i) << 6) | (a = _keyStr.indexOf(t.charAt(u++)))), (c += String.fromCharCode(e)), 64 != i && (c += String.fromCharCode(r)), 64 != a && (c += String.fromCharCode(n)) return c }

function _u_d(t) {
for (var e = '', r = 0, n = 0, o = 0, i = 0; r < t.length; )
(n = t.charCodeAt(r)) < 128
? ((e += String.fromCharCode(n)), r++)
: n > 191 && n < 224
? ((o = t.charCodeAt(r + 1)), (e += String.fromCharCode(((31 & n) << 6) | (63 & o))), (r += 2))
: ((o = t.charCodeAt(r + 1)), (i = t.charCodeAt(r + 2)), (e += String.fromCharCode(((15 & n) << 12) | ((63 & o) << 6) | (63 & i))), (r += 3))
return e
}

function d2(t) {
for (var e = '', r = 0; r < t.length; r++) {
var _p = 'W5D80NFZHAYB8EUI2T649RT2MNRMVE2O'
var n = _p.charCodeAt(r % _p.length)
e += String.fromCharCode(t.charCodeAt(r) ^ n)
}
return (e = _u_d(e))
}

const l = '密文'
var d = d1(l),
y = d2(d)

console.log(JSON.parse(y))

[/password]


JS逆向-数据接口返回加密数据如何进行解密

## Base64编码

是将一个8位字节序列拆散为6位的片段，并为每个6位的片段分配一个字符，这64个字符为：小写字母a-z、大写字母A-Z、数字0-9、符号"+"、"/" ，64是代表64个字符。

## 举例

y的二进制：`'y'.charCodeAt().toString(2)`

二进制转十进制：`parseInt('011110', 2)`
原数据you二进制011110010110111101110101重新分割011110010110111101110101对应十进制30226153查Base64编码表eW91
即‘you’的Base64编码为：eW91。

Base64编码：`window.btoa('you')`

Base64解码：`window.atob('eW91')`


Base64编码原理

## 注释

{# 注释 #}是注释。

## 变量替换

使用双花括号{{ }}来表示变量替换。例如，{{ name }}会被实际的值替换。

## 控制流语句

使用{% %}来表示控制流语句，如条件判断和循环迭代。

### if语句

    {% if age>=18 %}
    <p>成年</p>
    {% elif age>=7 %}
    <p>上学</p>
    {% else %}
    <p>小孩</p>
    {% endif %}

### for语句

    {% for like in likes %}
    <p>{{like}}：index-{{loop.index}} index0-{{loop.index0}} revindex-{{loop.revindex}} revindex0-{{loop.revindex0}}</p>
    {% endfor %}

配合if语句：

    {% for like in likes %}
      {% if loop.first %}
        <p style="color: red">{{like}}：index-{{loop.index}} index0-{{loop.index0}} revindex-{{loop.revindex}} revindex0-{{loop.revindex0}}</p>
      {% elif loop.last %}
        <p style="color: blue">{{like}}：index-{{loop.index}} index0-{{loop.index0}} revindex-{{loop.revindex}} revindex0-{{loop.revindex0}}</p>
      {% else %}
        <p>{{like}}：index-{{loop.index}} index0-{{loop.index0}} revindex-{{loop.revindex}} revindex0-{{loop.revindex0}}</p>
      {% endif %}
    {% endfor %}

## 过滤器

模板过滤器相当于函数，把当前的变量传入过滤器，过滤器根据自己的功能对变量进行相应的处理，再返回对应的值。语法：{{ 变量|过滤器|过滤器... }}

官方文档：[https://jinja.palletsprojects.com/en/3.0.x/templates/#builtin-filters](https://jinja.palletsprojects.com/en/3.0.x/templates/#builtin-filters)

## 结构标签

父模板挖坑，子模板填坑。
base.html：

    {% block blockname %}
    {% endblock %}

child.html:

    {# 继承父模板 #}
    {% extends "base.html" %}
    {% block blockname %}
    <p>Flask</p>
    {% endblock %}

child2.html:

    {% extends "child.html" %}
    {% block blockname %}
    {{ super() }}
    <p>Python</p>
    {% endblock %}

super()继承后保留父模板块中的内容。

include将其他模板包含进来：{% include "xxx.html" %}。

### 宏

类似函数：

    {# 宏定义 #}
    {% macro func(name, age) %}
    <p>姓名：{{name}}，年龄：{{age}}</p>
    {% endmacro %}
    {# 调用宏 #}
    {{ func('张三',18) }}

宏调用也可以用导入：{% from "xxx" import xxx %}。


Flask模板语言Template语法

## Flask

是一个基于Python实现的Web开发微框架（基于MVC设计模式），官方文档：[https://flask.palletsprojects.com/en/3.0.x/](https://flask.palletsprojects.com/en/3.0.x/)

安装Flask：`pip install flask`

查看Flask版本：`pip show flask`

## 插件

### Flask-SQLAlchemy

Flask-SQLAlchemy是对SQLAlchemy的一个封装，使得在Flask中使用SQLAlchemy更加方便。因为 Flask-SQLAlchemy依赖SQLAlchemy，所以只要安装了Flask-SQLAlchemy，SQLAlchemy会自动安装。

安装命令：`pip install flask-sqlalchemy`

Flask想要操作数据库，必须要先安装Python操作MySQL驱动，这里选用pymysql作为驱动程序，安装命令：`pip install pymysql`

### Flask-Migrate

Flask-Migrate是处理Flask应用程序SQLAlchemy数据库迁移的扩展。

安装命令：`pip install flask-migrate`

数据库操作可通过Flask命令行界面进行，ORM模型映射成表三步：

1. flask db init：这步只需执行一次
2. flask db migrate：识别ORM模型的改变，生成迁移脚本
3. flask db upgrade：运行迁移脚本，同步到数据库中

### Flask-Mail

在Flask中可使用Flask-Mail发送邮箱验证码。

安装命令：`pip install flask-mail`

### Flask-WTF

Flask-WTF是简化WTForms操作的第三方库。WTForms表单的两个主要功能是验证用户提交数据的合法性以及渲染模板，而Flask-WTF还包括一些其他的功能：CSRF保护，文件上传等。

安装Flask-WTF默认也会安装WTForms，安装命令：`pip install flask-wtf`

## run参数

    from flask import Flask
    app = Flask(name)
    @app.route("/")
    def index():
    return "Home"
    if name == "main":
    app.run(debug=True)

- debug：是否开启调试模式，开启后（默认关闭），修改保存Python代码后会自动重启，方便调试
- port：指定服务器端口号，默认是5000
- host：主机，默认是127.0.0.1，指定为0.0.0.0代表所有ip

## 返回值

### 返回字符串

    from flask import Flask
    app = Flask(name)
    @app.route("/")
    def index():
    return "<h1>Home</h1>"  # 1. 返回 字符串，支持HTML标签
    if name == "main":
    app.run(debug=True)

### 返回JSON

    from flask import Flask
    import json
    app = Flask(name)
    @app.route("/")
    def index():
    data = {"name": "张三", "age": 18}
    response = app.response_class(
    response=json.dumps(data, ensure_ascii=False),  # ensure_ascii设置为False，避免出现中文乱码
    status=200,
    mimetype="application/json",
    )
    return response
    if name == "main":
    app.run(debug=True)

若返回数据不包含中文：

    from flask import Flask, jsonify
    app = Flask(name)
    @app.route("/")
    def index():
    return jsonify({"name": "jack", "age": 18})
    if name == "main":
    app.run(debug=True)

### 模板渲染

templates\index.html文件：

    <!DOCTYPE html>
    <html lang="zh-CN">
    <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>首页</title>
    <link rel="stylesheet" href="{{ url_for('static',filename='index.css')}}" />
    </head>
    <body>
    <h2>{{name}}</h2>
    </body>
    </html>

static\index.css文件：

    h2 {
    color: red;
    }

app.py文件：

    from flask import Flask, render_template
    app = Flask(name)
    @app.route("/")
    def index():
    return render_template("index.html", name="张三")
    if name == "main":
    app.run(debug=True)

### 自定义Response对象

    from flask import Flask, make_response
    app = Flask(name)
    @app.route("/")
    def index():
    html = "<h1>Home</h1>"
    res = make_response(html, 200)
    return res
    if name == "main":
    app.run(debug=True)

也可以使用Flask的响应对象类Response，它允许更灵活地创建和自定义响应对象，以满足特定需求。对于更复杂的自定义响应，使用Response类会更有优势。

### 重定向

    from flask import Flask, redirect
    app = Flask(name)
    @app.route("/")
    def index():
    return redirect("https://www.baidu.com/")
    # return redirect("/home/")  # 也可以这么用
    if name == "main":
    app.run(debug=True)

url_for反向解析，通过视图函数发过来找路由，url_for("蓝图名称.视图函数名")。

    from flask import Flask, redirect, Blueprint, url_for
    app = Flask(name)
    blue = Blueprint("user", name)
    @blue.route("/response/")
    def get_response():
    return "response ok"
    @blue.route("/")
    def index():
    ret = url_for("user.get_response")
    return redirect(ret)
    if name == "main":
    app.register_blueprint(blueprint=blue)
    app.run(debug=True)

url_for也能传参：url_for("user.get_response", name="张三", age=18)。

## 请求Request

服务器在接收到客户端的请求后，Flask框架会自动创建Request对象，Request对象不可修改。属性有：

- url 完整请求地址
- base_url 去掉GET参数的URL
- host_url 只有主机和端口号的URL
- path 路由中的路径
- method 请求方法
- remote_addr 请求的客户端地址
- args GET请求参数
- form POST请求参数
- files 文件上传
- headers 请求头
- cookies 请求中的cookie

类字典结构对象，获取指定key值：dict.get('key')和dict.getlist('key')。

## 路由参数

### string

    @app.route("/string/<name>/")
    def get_name(name):
    return name

### int

    @app.route("/int/<int:id>/")
    def get_int(id):
    return str(id)

### float

    @app.route("/float/<float:pi>/")
    def get_float(pi):
    return str(pi)

### path

支持/的字符串，例如/path/3/14/，返回3/14。

    @app.route("/path/<path:name>/")
    def get_path(name):
    return str(name)

### uuid

    @app.route("/get-uuid/")
    def get_uuid():
    import uuid
    return str(uuid.uuid4())
    @app.route("/uuid/<uuid:id>/")
    def uuid(id):
    return str(id)

### any

从列出的项目中选择一个。

    @app.route("/any/<any(apple,orange, banana):fruit>/")
    def get_any(fruit):
    return str(fruit)

## 项目拆分

    Project
    |   app.py
    |
    ---App
    |   models.py
    |   views.py
    |   init.py
    |
    +---static
    |       index.css
    |
    +---templates
    |       index.html

## cookie

App\templates\index.html文件：

    <!DOCTYPE html>
    <html lang="zh-CN">
    <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>首页</title>
    <link rel="stylesheet" href="{{ url_for('static',filename='index.css')}}" />
    </head>
    <body>
    <h2>首页</h2>
    <hr />
    {% if username %}
    <p>当前登录用户：{{username}} <a href="/logout/">注销</a></p>
    {% else %}
    <a href="/login/">登录</a>
    {% endif %}
    </body>
    </html>

App\templates\login.html文件：

    <!DOCTYPE html>
    <html lang="zh-CN">
    <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    </head>
    <body>
    <h2>登录</h2>
    <hr />
    &lt;form action=&quot;&quot; method=&quot;post&quot;&gt;
      &lt;p&gt;用户名：&lt;input type=&quot;text&quot; name=&quot;username&quot; /&gt;&lt;/p&gt;
      &lt;p&gt;密码：&lt;input type=&quot;password&quot; name=&quot;password&quot; /&gt;&lt;/p&gt;
      &lt;p&gt;&lt;button&gt;提交&lt;/button&gt;&lt;/p&gt;
    &lt;/form&gt;
    
    </body>
    </html>

App\views.py文件：

    import datetime
    from flask import Blueprint, request, render_template, redirect
    from .models import *
    创建蓝图
    blue = Blueprint("user", name)
    @blue.route("/")
    def index():
    # 4. 获取cookie
    username = request.cookies.get("user")
    return render_template("index.html", username=username)
    @blue.route("/login/", methods=["GET", "POST"])
    def login():
    if request.method == "GET":
    return render_template("login.html")
    elif request.method == "POST":
    # 1. 获取前端提交过来的数据
    username = request.form.get("username")
    password = request.form.get("password")
        # 2. 模拟登录：用户名和密码验证
        if username == &quot;admin&quot; and password == &quot;123&quot;:
            response = redirect(&quot;/&quot;)
    
            # 3. 设置cookie
            response.set_cookie(&quot;user&quot;, username)  # 浏览器关闭失效
            # response.set_cookie(&quot;user&quot;, username, max_age=3600 * 24)  # 过期时间 秒
            # response.set_cookie(
            #     &quot;user&quot;, username, expires=datetime.datetime(2023, 12, 31)
            # )
    
            return response
        else:
            return &quot;用户名或密码错误！&quot;
    
    @blue.route("/logout/")
    def logout():
    response = redirect("/")
    # 5. 删除cookie
    response.delete_cookie("user")
    return response</code></pre><h2>session</h2><p>App\views.py文件：</p><pre><code class="lang-python">import datetime
    
    from flask import Blueprint, request, render_template, redirect, session
    from .models import *
    创建蓝图
    blue = Blueprint("user", name)
    @blue.route("/")
    def index():
    # 4. 获取session
    username = session.get("user")
    return render_template("index.html", username=username)
    @blue.route("/login/", methods=["GET", "POST"])
    def login():
    if request.method == "GET":
    return render_template("login.html")
    elif request.method == "POST":
    # 1. 获取前端提交过来的数据
    username = request.form.get("username")
    password = request.form.get("password")
        # 2. 模拟登录：用户名和密码验证
        if username == &quot;admin&quot; and password == &quot;123&quot;:
            response = redirect(&quot;/&quot;)
    
            # 3. 设置session
            session[&quot;user&quot;] = username
            session.permanent = True
    
            return response
    
        else:
            return &quot;用户名或密码错误！&quot;
    
    @blue.route("/logout/")
    def logout():
    response = redirect("/")
    # 5. 删除session
    session.pop("user")
    # session.clear()  # 慎用，会删除所有session
    return response</code></pre><p>还需要配置session，App\__init__.py文件：</p><pre><code class="lang-python">import datetime
    
    from flask import Flask
    from .views import blue
    def create_app():
    app = Flask(name)
    # 注册蓝图
    app.register_blueprint(blueprint=blue)
    # session配置
    # print(app.config)  # Flask配置信息
    app.config[&quot;SECRET_KEY&quot;] = &quot;abc123&quot;
    app.config[&quot;PERMANENT_SESSION_LIFETIME&quot;] = datetime.timedelta(days=3)
    
    return app</code></pre>
    
    


Python轻量级Web应用框架Flask学习笔记

这里是 aboss.top 的自留地。写了十几年野路子代码，攒了些摸爬滚打的经验，做成系列课程慢慢讲；也留了一小块地方，记记代码之外的胡思乱想。