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hsz1273327 · Mar 31, 2023 · 2bae5e6 · 2bae5e6
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diff --git a/src/.DS_Store b/src/.DS_Store
diff --git a/src/术语表/.DS_Store b/src/术语表/.DS_Store
diff --git a/src/虚拟机篇/python的虚拟机.ipynb b/src/虚拟机篇/python的虚拟机.ipynb
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+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# CPython的虚拟机\n",
+    "\n",
+    "CPython 使用一个基于栈的虚拟机.也就是说它完全面向栈数据结构的(你可以\"推入(push)\"一个东西到栈顶，或者从栈顶上\"弹出(pop)\"一个东西来).\n",
+    "\n",
+    "CPython 使用三种类型的栈:\n",
+    "\n",
+    "+ 调用栈(call stack)\n",
+    "\n",
+    "    这是运行 Python 程序的主要结构.它为每个当前活动的函数调用使用了一个东西--\"帧(frame)\".栈底是程序的入口点.每个函数调用推送一个新的帧到调用栈,每当函数调用返回后,这个帧被销毁.\n",
+    "    \n",
+    "+ 计算栈(evaluation stack)\n",
+    "\n",
+    "    也称为数据栈(data stack).在每个帧中有一个计算栈.这个栈就是 Python 函数运行的地方.运行的 Python 代码大多数是由推入到这个栈中的东西组成的,这个栈负责操作它们.然后在返回后销毁它们。\n",
+    "\n",
+    "+ 块栈(block stack)\n",
+    "\n",
+    "    在每个帧中还有一个块栈.它被 Python 用于去跟踪某些类型的控制结构--循环、`try / except 块`、以及 `with 块`，全部推入到块栈中,当你退出这些控制结构时块栈被销毁.这将帮助 Python 了解任意给定时刻哪个块是活动的.比如，一个 continue 或者 break 语句可能影响正确的块.\n",
+    "    \n",
+    "    \n"
+   ]
+  },
+  {
+   "cell_type": "code",
+   "execution_count": null,
+   "metadata": {},
+   "outputs": [],
+   "source": []
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.6.4"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}
diff --git a/src/虚拟机篇/编译与反编译.ipynb b/src/虚拟机篇/编译与反编译.ipynb
@@ -0,0 +1,152 @@
+{
+ "cells": [
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "# 编译与反编译\n",
+    "\n",
+    "首先说明下本文的python特指官方的Cpython实现.\n",
+    "\n",
+    "python外界的定义是解释型语言,其原理是将代码放入解释器,解释一句执行一句.然而实际上python的执行流程会比这个略微复杂一些.python源码到执行的中间会有一个步骤生成字节码,实际执行的其实是这个字节码.因此,如果想跳过第一步,我们可以对源码进行编译,编译为字节码后直接执行字节码."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## python的字节码\n",
+    "\n",
+    "cpython实际上运行的是字节码,我们所写的python源文件之所以可以被执行,其原因是当python程序加载时,源文件会被先翻译为字节码.然后保存在同级文件的`__pycache__`文件夹下.下次执行是,如果`__pycache__`下的字节码文件和源码文件修改时间匹配一致就会直接执行`__pycache__`中缓存的字节码,不一致则会将对应的字节码替换.\n",
+    "\n",
+    "\n",
+    "python的字节码在旧版本中有两种,一种是常规的`.pyc`文件,其加载速度相对于之前的.py文件有所提高,而且还可以实现源码隐藏,以及一定程度上的反编译;另一种是经过优化的`.pyo`文件(相比于`.pyc`文件更小),也可以提高加载速度.\n",
+    "\n",
+    "而现在则统一都是以`.pyc`作为后缀,优化的等级则显式的放在编译后文件的命名上."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "### 编译模块到`.pyc`\n",
+    "\n",
+    "编译到`.pyc`我们可以使用两个标准库提供的工具:\n",
+    "\n",
+    "+ `py_compile`用于编译单独的源码文件\n",
+    "\n",
+    "+ `compileall`用于将某个文件夹下的源码文件递归地进行编译\n",
+    "\n",
+    "#### **单文件编译**\n",
+    "\n",
+    "使用`py_compile`单独编译一个文件的话,可以使用命令行工具\n",
+    "\n",
+    "```shell\n",
+    "python -m py_compile /path/to/需要生成.pyc的脚本.py\n",
+    "```\n",
+    "即可.\n",
+    "\n",
+    "也可以在python脚本下使用,调用`py_compile`:\n",
+    "\n",
+    "```python\n",
+    "py_compile.compile(file[, cfile[, dfile[, doraise]]])\n",
+    "```\n",
+    "\n",
+    "其中\n",
+    "+ `file`,表示需要生成`.pyc`或`.pyo`文件的源码路径;\n",
+    "+ `cfile`，表示需要生成`.pyc`或`.pyo`文件的目标文件路径.它默认是以`.pyc`为扩展名的形如`xxxx.cpython-36.pyc`这样形式的字符串.此外，当且仅当所使用的解释器允许编译成.pyo文件,才能以`.pyo`结尾,这个后文说.\n",
+    "+ `dfile`,表示编译出错时,将报错信息中的名字`file`替换为`dfile`\n",
+    "+ `doraise`，设置是否忽略异常.若为`True`,则抛出`PyCompileError`异常;否则直接将错误信息写入`sys.stderr`.\n",
+    "\n",
+    "\n",
+    "类似的,编译整个文件夹可以使用命令行工具`compileall`\n",
+    "\n",
+    "```shell\n",
+    "python -m compileall <dir>\n",
+    "```\n",
+    "\n",
+    "常用的参数有`-b`表示写入它们源文件同级并且同名不同后缀\n",
+    "\n",
+    "也可以在python脚本下使用,调用`compileall`:\n",
+    "\n",
+    "```python\n",
+    "import compileall\n",
+    "\n",
+    "compileall.compile_dir('Lib/', force=True)\n",
+    "```\n",
+    "compile_dir参数有:\n",
+    "\n",
+    "+ `dir`目标文件夹\n",
+    "+ `maxlevels=10`文件夹最大递归深度\n",
+    "+ `ddir=None`检查ddir中二进制文件的时间戳,如果与目标文件不一致才会编译\n",
+    "+ `force=False`强制编译\n",
+    "+ `rx=None`使用`re`查找目标文件夹下要编译的文件\n",
+    "+ `quiet=0`是否输出编译过程\n",
+    "+ `legacy=False`字节码文件是否被写入它们源文件同级并且同名(python2的默认编译行为),它们可能覆盖由另一版本的Python创建的字节码文件\n",
+    "+ `optimize=-1`优化等级,\n",
+    "+ `workers=1`多进程编译\n",
+    "\n",
+    "\n",
+    "#### **编译优化**\n",
+    "\n",
+    "使用命令行工具编译是否优化的标志位在python一级,使用`-O`表示优化等级为1,`-OO`表示优化等级为2级(相比1级去掉了文档字符串),经过优化的字节码文件会被默认的命名为`xxxx.cpython-36.opt-2.pyc`这样的形式.\n",
+    "\n",
+    "单文件的1级优化编译\n",
+    "\n",
+    "```shell\n",
+    "python -O -m py_compile /path/to/需要生成.pyo的脚本.py\n",
+    "```\n",
+    "\n",
+    "文件夹下递归2级优化编译:\n",
+    "\n",
+    "```shell\n",
+    "python -O -m compileall -b <path>\n",
+    "```\n",
+    "\n",
+    "需要注意编译后的字节码文件并不会提高运行时的执行速度,只会提高模块的加载速度."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## 反编译\n",
+    "\n",
+    "指望通过编译python源文件来反编译是不现实的,使用`uncompyle6`工具可以非常轻易的将`.pyc`反编译为源码`.py`文件.`uncompyle6`可以直接使用`pip`工具安装."
+   ]
+  },
+  {
+   "cell_type": "markdown",
+   "metadata": {},
+   "source": [
+    "## 结语\n",
+    "\n",
+    "python的编译功能看起来挺鸡肋的,但还是可以在一些特定环境下发挥用处的,比如:\n",
+    "\n",
+    "+ 硬盘空间资源紧张的硬件上,像树莓派,结合`zipapp`,可执行文件可以被控制在一个很小的程度.\n",
+    "+ 吓唬外行,通常知道点python的也不会知道可以`编译`,编译后的字节码人类也是没法直接解读的,一定程度上可以防止源码泄漏\n"
+   ]
+  }
+ ],
+ "metadata": {
+  "kernelspec": {
+   "display_name": "Python 3",
+   "language": "python",
+   "name": "python3"
+  },
+  "language_info": {
+   "codemirror_mode": {
+    "name": "ipython",
+    "version": 3
+   },
+   "file_extension": ".py",
+   "mimetype": "text/x-python",
+   "name": "python",
+   "nbconvert_exporter": "python",
+   "pygments_lexer": "ipython3",
+   "version": "3.6.4"
+  }
+ },
+ "nbformat": 4,
+ "nbformat_minor": 2
+}