[Python] How does python bytecode works?

http://en.wikipedia.org/wiki/Bytecode

Nope. The CPython Python interpreter is written in (as portable as
possible) C. The Jython, IronPython, and PyPy Python interpreters are
written in Jave, C#, and Python respectively. Each compiles Python to
something different. I presume each (normally) saves the compiled form
until the source changes. CPython compiles to CPython-specific bytecode.
It saves the bytecode as a .pyc file in a .__cache__ subdirectory (in 3.2+).
Yes it is (mostly). CPython has been compilied, with minor adjustments,
on numerous (>20) systems.
The Python interpreter of the website *does* compile Python code to
whatever it compiles to.

Badly written C is not portable. But C is probably the most portable
language on the planet, by virtue of basically every system having a C
compiler backend.

The issue is that a lot of people make nonportable assumptions about
C, and runtimes / OSes / architectures are free to make lots of very
weird decisions.

For example, this code is not strictly universally-compatible C. It is
"portable" in that the changes required to make it run on any system
are trivial, but not in the sense that it should be able to compile
without any changes. (Not unless a cheeky/smart compiler is involved,
anyway).

int main () {
return 0;
}

Instead of 0, it should "technically" return EXIT_SUCCESS AIUI. Most
people don't care because EXIT_SUCCESS is 0 almost everywhere.
Apache is written in C, and can embed CPython. This is easy enough,
because CPython is written in C, and C works well with other C code.
CPython itself can communicate with Python code, because it is
directly responsible for running Python code. So the server
communicates with CPython, and CPython communicates with the Python
code. At no time does Python code ever "directly" touch anything other
than the interpreter.


The bytecode doesn't really have much to do with all this, except that
it is the specific thing that CPython works with.

-- Devin

In the interests of pedantry, I will point out that the C standard
requires implementation to treat both 0 and EXIT_SUCCESS to be treated
as successful exits. The implementation must translate this to
whatever the environment treats as successful termination of the
program. Ref: specification of the exit(int) function.

Yes, at least CPython is. Of course, java is written in C, as are many
other languages.

C gives you lots of rope to hang yourself with, but if you use C well, it's
more portable than anything else, including the "portable" languages (the
ones that don't give you much rope).

I guess this is kind of like asking how you breathe. Python just gets
exec'd or dlopen'd or something.

CPython is to .pyc as java is to .class. They're both byte-compiled. Java
is more commonly JIT compiled than CPython, but Python in general does
allow JIT compilation.

IOW, CPython is compiled, it just doesn't burden the developer with a
separate compile step.

Please see above.

You may get better answers if you get into more specifics about what your
question really is.