python 的逆向工程

什么是pyc文件

pyc是一種二進制文件，是由py文件經(jīng)過編譯后，生成的文件，是一種byte code，py文件變成pyc文件后，加載的速度有所提高，而且pyc是一種跨平臺的字節(jié)碼，是由python的虛擬機來執(zhí)行的，這個是類似于JAVA或者.NET的虛擬機的概念。pyc的內(nèi)容，是跟python的版本相關(guān)的，不同版本編譯后的pyc文件是不同的，2.5編譯的pyc文件，2.4版本的 python是無法執(zhí)行的。

什么是pyo文件

pyo是優(yōu)化編譯后的程序 python -O 源文件即可將源程序編譯為pyo文件 

什么是pyd文件

pyd是python的動態(tài)鏈接庫。

這里的pyo 優(yōu)化后的字節(jié)碼？這種優(yōu)化怎么理解，還有就是pyd 這個編譯的動態(tài)鏈接庫如何理解？

回答

編輯回答

乖乖噠

1. 關(guān)于 `pyo` 優(yōu)化:

參考鏈接

When the Python interpreter is invoked with the -O flag, optimized code is generated and stored in .pyo files. The optimizer currently doesn't help much; it only removes assert statements. When -O is used, all bytecode is optimized; .pyc files are ignored and .py files are compiled to optimized bytecode.
Passing two -O flags to the Python interpreter (-OO) will cause the bytecode compiler to perform optimizations that could in some rare cases result in malfunctioning programs. Currently only __doc__ strings are removed from the bytecode, resulting in more compact .pyo files. Since some programs may rely on having these available, you should only use this option if you know what you're doing.
Your program doesn't run any faster when it is read from a .pyc or .pyo file than when it is read from a .py file; the only thing that's faster about .pyc or .pyo files is the speed with which they are loaded.
When a script is run by giving its name on the command line, the bytecode for the script is never written to a .pyc or .pyo file. Thus, the startup time of a script may be reduced by moving most of its code to a module and having a small bootstrap script that imports that module. It is also possible to name a .pyc or .pyo file directly on the command line.

2. 關(guān)于 `pyd`:

pyd 可以理解為 Windows DLL 文件。

參考鏈接

Yes, .pyd files are dll’s, but there are a few differences. If you have a DLL named foo.pyd, then it must have a function PyInit_foo(). You can then write Python "import foo", and Python will search for foo.pyd (as well as foo.py, foo.pyc) and if it finds it, will attempt to call PyInit_foo() to initialize it. You do not link your .exe with foo.lib, as that would cause Windows to require the DLL to be present.
Note that the search path for foo.pyd is PYTHONPATH, not the same as the path that Windows uses to search for foo.dll. Also, foo.pyd need not be present to run your program, whereas if you linked your program with a dll, the dll is required. Of course, foo.pyd is required if you want to say import foo. In a DLL, linkage is declared in the source code with __declspec(dllexport). In a .pyd, linkage is defined in a list of available functions.