1 什么是pyc文件
1.1 什么是pyc文件
1、pyc文件：是由Python文件经过编译后所生成的文件，它是一种字节码 byte code，因此我们直接查看就是乱码的，也对源码起到一定的保护作用，但是这种字节码byte code是可以反编译的，后面会介绍！
我们都知道计算机是不认识你在代码里写的那一行行字母的，计算机只认二进制，也只执行二进制文件，我们写的代码是需要编译器编译成二进制的。（参考）
对于Python来说你写的Python代码在执行python xxx.py时会由Python解析器翻译成PyCodeObject对象，俗称字节码(byte code)，然后交由Python虚拟机来执行字节码（PS：字节码才是可执行的）。
在这个过程中这些字节码都是在内存中的，众所周知Python的运行性能不如编译性语言(比如C语言，JAVA …)，所以Python在程序执行结束后会把字节码写入到硬盘中，保存为.pyc文件，目的是下一次再执行python xxx.py程序时，Python会先在目录下找xxx.pyc文件来执行，因为.pyc文件里保存的是字节码，所以就节省了Python解析器把xxx.py翻译成字节码的时间，所以就提高了性能。
总结就是.pyc文件是一个可执行的字节码文件，目的是节省Python解析器翻译时间，提高运行效率。其实性能只会提高那么一丢丢，大型项目.py文件很多的话，猿人学Python测试过节省的时间就多一点。
2、我们同样可以像执行py文件一样来执行pyc文件，例如：
python test.pypython test.pyc
注意：
必须保证编译成pyc文件的python解释器版本和现在执行的python解释器版本保持一致，否则会报错，如下我导入deepsocial.pyc文件中的模块是报错：ImportError: bad magic number in 'deepsocial': b'B\r\r\n'
from deepsocial import *
ImportError: bad magic number in 'deepsocial': b'B\r\r\n'
1.2 pyc文件是怎么生成的，有什么好处
从上面的介绍我们已经知道pyc的好处主要是：
- 由于
pyc源码的不可见，因此可以起到保护代码安全性的作用，但也不是绝对的，因为pyc文件是可以被反编译 pyc文件可以提高代码的执行效率
pyc的内容与python的版本相关，不同版本编译的pyc文件不一样
2 把python的py文件编译成pyc文件
下面我测试的文件目录结构：
(yolov4) shl@zhihui-mint:~/shl_res/5_new_project$ tree test/
test/
├── deepsocial.py
└── scripts
└── run.py
1 directory, 2 files
(yolov4) shl@zhihui-mint:~/shl_res/5_new_project$
2.1 使用python内置库py_compile把单个py文件编译成pyc文件
1、使用py_compile把单个py文件编译成pyc文件
(yolov4) shl@zhihui-mint:~/shl_res/5_new_project/test$ ls
deepsocial.py scripts
(yolov4) shl@zhihui-mint:~/shl_res/5_new_project/test$ python
Python 3.6.12 |Anaconda, Inc.| (default, Sep 8 2020, 23:10:56)
[GCC 7.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import py_compile
>>> py_compile.compile("./deepsocial.py")
'./__pycache__/deepsocial.cpython-36.pyc'
>>>
生成文件如下：
(yolov4) shl@zhihui-mint:~/shl_res/5_new_project/test$ tree
.
├── deepsocial.py
├── __pycache__
│ └── deepsocial.cpython-36.pyc
└── scripts
└── run.py
2 directories, 3 files
(yolov4) shl@zhihui-mint:~/shl_res/5_new_project/test$
2.2 使用python内置库compileall把多个py文件编译成pyc文件
2.2.1 使用python -m compileall命令把多个py文件编译成pyc文件
1、首先来查看python -m compileall有哪些参数
(yolov4) shl@zhihui-mint:~/shl_res/5_new_project/test$ python -m compileall -h
usage: compileall.py [-h] [-l] [-r RECURSION] [-f] [-q] [-b] [-d DESTDIR]
[-x REGEXP] [-i FILE] [-j WORKERS]
[FILE|DIR [FILE|DIR ...]]
Utilities to support installing Python libraries.
positional arguments:
FILE|DIR zero or more file and directory names to compile; if
no arguments given, defaults to the equivalent of -l
sys.path
optional arguments:
-h, --help show this help message and exit
-l don't recurse into subdirectories
-r RECURSION control the maximum recursion level. if `-l` and `-r`
options are specified, then `-r` takes precedence.
-f force rebuild even if timestamps are up to date
-q output only error messages; -qq will suppress the
error messages as well.
-b use legacy (pre-PEP3147) compiled file locations
-d DESTDIR directory to prepend to file paths for use in compile-
time tracebacks and in runtime tracebacks in cases
where the source file is unavailable
-x REGEXP skip files matching the regular expression; the regexp
is searched for in the full path of each file
considered for compilation
-i FILE add all the files and directories listed in FILE to
the list considered for compilation; if "-", names are
read from stdin
-j WORKERS, --workers WORKERS
Run compileall concurrently
(yolov4) shl@zhihui-mint:~/shl_res/5_new_project/test$
2、把单个py文件生成pyc文件，例如
python -m compileall deepsocial.py
3、递归的把当前目录下所有的py文件都生成对应的pyc文件
python -m compileall .
注意：
后面有一个点.， 表示当前目录！
2.2.2 使用compileall的API把多个py文件编译成pyc文件
如下，是通过调用compileall的API接口，递归的把指定目录下所有的py文件都生成对应的pyc文件！
>>> import compileall
>>> compileall.compile_dir("/home/shl/shl_res/5_new_project/test")
Listing '/home/shl/shl_res/5_new_project/test'...
Compiling '/home/shl/shl_res/5_new_project/test/deepsocial.py'...
Listing '/home/shl/shl_res/5_new_project/test/scripts'...
Compiling '/home/shl/shl_res/5_new_project/test/scripts/run.py'...
True
>>>
3 使用uncomplye6工具把pyc文件反编译成py文件
只有pyc文件可以运行程序，但是是不能获取程序源码的。同时如果python的版本和pyc版本使用的不同，那么程序会闪退。对pyc文件进行反编译需要用到python第三方库包uncompyle。
3.1 使用uncomplye6工具安装
3.1.1 uncomplye6介绍
1、uncomplye6介绍
uncomplye6继承了decompyle、uncompyle 和uncompyle2。uncompyle6可将python字节码转换回等效的python源代码，它接受python 1.3版到3.8版的字节码。
2、uncomplye6的github地址
3.1.2 uncomplye6安装
1、pip安装
pip install uncomplye6
2、从源码安装
git clone https://github.com.cnpmjs.org/rocky/python-uncompyle6.git
编译：
$cd python-uncompyle6
$pip install -e . # set up to run from source tree
# Or if you want to install instead
$python setup.py install # may need sudo
3.2 使用uncomplye6工具把pyc反编译为py文件的具体使用
3.2.1 查看uncomplye6的参数
1、安装好uncomplye6后，可以使用uncomplye6 -h从
(yolov4) shl@zhihui-mint:~/shl_res/5_new_project/DeepSOCIAL$ python -V
Python 3.6.12 :: Anaconda, Inc.
(yolov4) shl@zhihui-mint:~/shl_res/5_new_project/DeepSOCIAL$ uncompyle6 -V
uncompyle6 3.7.4
(yolov4) shl@zhihui-mint:~/shl_res/5_new_project/DeepSOCIAL$ uncompyle6 -h
Usage:
uncompyle6 [OPTIONS]... [ FILE | DIR]...
uncompyle6 [--help | -h | --V | --version]
Examples:
uncompyle6 foo.pyc bar.pyc # decompile foo.pyc, bar.pyc to stdout
uncompyle6 -o . foo.pyc bar.pyc # decompile to ./foo.pyc_dis and ./bar.pyc_dis
uncompyle6 -o /tmp /usr/lib/python1.5 # decompile whole library
Options:
-o <path> output decompiled files to this path:
if multiple input files are decompiled, the common prefix
is stripped from these names and the remainder appended to
<path>
uncompyle6 -o /tmp bla/fasel.pyc bla/foo.pyc
-> /tmp/fasel.pyc_dis, /tmp/foo.pyc_dis
uncompyle6 -o /tmp bla/fasel.pyc bar/foo.pyc
-> /tmp/bla/fasel.pyc_dis, /tmp/bar/foo.pyc_dis
uncompyle6 -o /tmp /usr/lib/python1.5
-> /tmp/smtplib.pyc_dis ... /tmp/lib-tk/FixTk.pyc_dis
--compile | -c <python-file>
attempts a decompilation after compiling <python-file>
-d print timestamps
-p <integer> use <integer> number of processes
-r recurse directories looking for .pyc and .pyo files
--fragments use fragments deparser
--verify compare generated source with input byte-code
--verify-run compile generated source, run it and check exit code
--syntax-verify compile generated source
--linemaps generated line number correspondencies between byte-code
and generated source output
--encoding <encoding>
use <encoding> in generated source according to pep-0263
--help show this message
Debugging Options:
--asm | -a include byte-code (disables --verify)
--grammar | -g show matching grammar
--tree={
before|after}
-t {
before|after} include syntax before (or after) tree transformation
(disables --verify)
--tree++ | -T add template rules to --tree=before when possible
Extensions of generated files:
'.pyc_dis' '.pyo_dis' successfully decompiled (and verified if --verify)
+ '_unverified' successfully decompile but --verify failed
+ '_failed' decompile failed (contact author for enhancement)
(yolov4) shl@zhihui-mint:~/shl_res/5_new_project/DeepSOCIAL$
3.2.2 使用uncompyle6命令把pyc反编译成py文件
1、首先我们可以去下载一个pyc文件（我正式因为看不到它的源码，才去搞的这个）
wget https://github.com.cnpmjs.org/DrMahdiRezaei/DeepSOCIAL/blob/master/deepsocial.pyc
2、使用uncompyle6命令把pyc反编译成py文件
uncompyle6 deepsocial.pyc > deepsocial.py
或
uncompyle6 -o deepsocial.py deepsocial.pyc
输出的deepsocial.py文件开头会多一段这样的注释：
# uncompyle6 version 3.7.4
# Python bytecode 3.7 (3394)
# Decompiled from: Python 3.6.12 |Anaconda, Inc.| (default, Sep 8 2020, 23:10:56)
# [GCC 7.3.0]
# Embedded file name: deepsocial.py
# Compiled at: 2021-03-06 05:54:51
# Size of source mod 2**32: 14036 bytes
说明：
uncompyle6 version 3.7.4：uncompyle6工具的版本是3.7.4Python bytecode 3.7：deepsocial.pyc字节码byte code文件是使用python3.7生成的，因此要执行pyc文件，必须要python的版本也是3.7版本才可以！Decompiled from: Python 3.6.12：我解码pyc使用的是python版本是3.6.12
3、将当前文件夹中所有的 pyc 文件反编译成后缀名为.pyc_dis 的源文件
uncompile -o . *.pyc
4 python编译的如何设置不生成pyc文件
pyc文件一般是在使用import导入另一个模块的时候会生成，python3会把生成的pyc文件存储在__pycache__目录下。
那如何让python编译的时候不生成pyc文件呢，有如下几种方法：
方法一：使用-B参数 即
python -B test.py
可以使用python -h查看参数的含义：
(base) shl@zhihui-mint:~$ python -h
usage: python [option] ... [-c cmd | -m mod | file | -] [arg] ...
Options and arguments (and corresponding environment variables):
-b : issue warnings about str(bytes_instance), str(bytearray_instance)
and comparing bytes/bytearray with str. (-bb: issue errors)
-B : don't write .pyc files on import; also PYTHONDONTWRITEBYTECODE=x
-c cmd : program passed in as string (terminates option list)
-d : debug output from parser; also PYTHONDEBUG=x
-E : ignore PYTHON* environment variables (such as PYTHONPATH)
-h : print this help message and exit (also --help)
-i : inspect interactively after running script; forces a prompt even
if stdin does not appear to be a terminal; also PYTHONINSPECT=x
-I : isolate Python from the user's environment (implies -E and -s)
-m mod : run library module as a script (terminates option list)
-O : remove assert and __debug__-dependent statements; add .opt-1 before
.pyc extension; also PYTHONOPTIMIZE=x
-OO : do -O changes and also discard docstrings; add .opt-2 before
.pyc extension
-q : don't print version and copyright messages on interactive startup
-s : don't add user site directory to sys.path; also PYTHONNOUSERSITE
-S : don't imply 'import site' on initialization
-u : force the stdout and stderr streams to be unbuffered;
this option has no effect on stdin; also PYTHONUNBUFFERED=x
-v : verbose (trace import statements); also PYTHONVERBOSE=x
can be supplied multiple times to increase verbosity
-V : print the Python version number and exit (also --version)
when given twice, print more information about the build
-W arg : warning control; arg is action:message:category:module:lineno
also PYTHONWARNINGS=arg
-x : skip first line of source, allowing use of non-Unix forms of #!cmd
方法二：设置环境变量
export PYTHONDONTWRITEBYTECODE=1
方法三：在导入的地方设置如下
import sys
sys.dont_write_bytecode = True
参考：https://www.yuanrenxue.com/tricks/what-is-pyc-file.html # 对pyc文件解释比较清楚
参考：https://www.php.cn/python-tutorials-416352.html # 把py文件生成pyc文件
