Generating .pyc/.pyo from a make file

[Tim Daneliuk]

I use a makefile to create distribution tarballs of freestanding Python
programs and their documentation. I cannot seem to find the right
command line option to just generate a pyc/pyo file from the program
and then exit. If I use 'python -OOOO -c"import myprog"' it creates
the pyo file, but myprog starts up and keeps running.

IOW, I need a batch method for generating compiled python. I know it
exists, but I can't find it for some reason ...

TIA,

 

[Roland Heiber]

I use a makefile to create distribution tarballs of freestanding Python
programs and their documentation. I cannot seem to find the right
command line option to just generate a pyc/pyo file from the program
and then exit. If I use 'python -OOOO -c"import myprog"' it creates
the pyo file, but myprog starts up and keeps running.

IOW, I need a batch method for generating compiled python. I know it
exists, but I can't find it for some reason ...

TIA,

Hi,

take a look at http://docs.python.org/lib/module-compileall.html

HtH, Roland

 

[Tim Daneliuk]

Hi,

take a look at http://docs.python.org/lib/module-compileall.html

HtH, Roland

It does - thanks. One more question: Are pyc and pyo file portable
across operating systems? I suspect not since I generated a pyo
on a FreeBSD machine that will not run on a Win32 machine. I was
under the impression that "compiled" meant optimized byte code that
was portable across implementations, but it looks to not be the case...

 

[Roland Heiber]

It does - thanks. One more question: Are pyc and pyo file portable
across operating systems? I suspect not since I generated a pyo
on a FreeBSD machine that will not run on a Win32 machine. I was
under the impression that "compiled" meant optimized byte code that
was portable across implementations, but it looks to not be the case...

Hi,

..pyc's should be, cause it's standard python-bytecode, if you use
massive optimizations it depends not on the os but on the underlying
cpu/architecture ...

So long, Roland

 

[Steve Holden]

Hi,

..pyc's should be, cause it's standard python-bytecode, if you use
massive optimizations it depends not on the os but on the underlying
cpu/architecture ...

So long, Roland

You probably tried to use a bytecode file from *one* version of Python
with an interpreter of another version. Python actually checks the first
four bytes of the .pyc file for a compatible "magic number" before
accepting the file for execution.

regards
Steve

 

[Tim Daneliuk]

You probably tried to use a bytecode file from *one* version of Python
with an interpreter of another version. Python actually checks the first
four bytes of the .pyc file for a compatible "magic number" before
accepting the file for execution.

regards
Steve

Aha! Exactly ... and that makes perfect sense too. D'oh! I guess a better
distribution strategy would be to have the installation program generate the pyo
file at installation time...

Thanks -

 

[Steve Holden]

Aha! Exactly ... and that makes perfect sense too. D'oh! I guess a
better
distribution strategy would be to have the installation program generate
the pyo
file at installation time...

Thanks -

That's what most sensible distributions do.

regards
Steve

 

[vincent wehren]

Aha! Exactly ... and that makes perfect sense too. D'oh! I guess a
better
distribution strategy would be to have the installation program generate
the pyo
file at installation time...

Thanks -

Also, the *.py? files contain the full pathname of the *.py they have
been compiled from. Copying them to other path locations will give you
the wrong __file___ information in tracebacks.

 

[Roland Heiber]

You where right, i was totally mislead by "optimized" ...

Greetings, Roland

 

[Just]

Also, the *.py? files contain the full pathname of the *.py they have
been compiled from.
True.

Copying them to other path locations will give you
the wrong __file___ information in tracebacks.

This is not 100% accurate: yes, the traceback shows the original source
file path, yet module.__file__ does point to the actual .pyc file it was
loaded from.

Just