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.py
• python 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'Brrn'

    from deepsocial import *
ImportError: bad magic number in 'deepsocial': b'Brrn'

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

• uncomplye6 github地址：https://github.com/rocky/python-uncompyle6

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3.7.4
• Python 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

最后

以上就是笑点低绿草为你收集整理的什么是pyc文件，把python的py文件编译成pyc文件，把pyc文件反编译成py文件。以及python编译的如何设置不生成pyc文件1 什么是pyc文件2 把python的py文件编译成pyc文件3 使用uncomplye6工具把pyc文件反编译成py文件4 python编译的如何设置不生成pyc文件的全部内容，希望文章能够帮你解决什么是pyc文件，把python的py文件编译成pyc文件，把pyc文件反编译成py文件。以及python编译的如何设置不生成pyc文件1 什么是pyc文件2 把python的py文件编译成pyc文件3 使用uncomplye6工具把pyc文件反编译成py文件4 python编译的如何设置不生成pyc文件所遇到的程序开发问题。

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