On Wed, 21 Oct 2020 14:19:37 +0200 Marco Sulla Marco.Sulla.Python@gmail.com wrote:

If not already present, do you think it's useful to add a macro that does something like

# ifdef Py_DEBUG fprintf(stderr, "%s\n", message); # endif

In general, you want to do this on a per-component basis, so each C source file tends to redefine its own macros if it needs to.

Regards

Antoine.

Hi,

There is the __debug__ builtin variable which is equal to True by default, but is equal to False when Python is run with the -O command line option.

The compiler removes dead code when -O is used. Example:

$ cat x.py def func(): if __debug__: print("debug")

import dis dis.dis(func)

# "debug" constant is checked at runtime $ python3 x.py 2 0 LOAD_GLOBAL 0 (print) 2 LOAD_CONST 1 ('debug') 4 CALL_FUNCTION 1 6 POP_TOP 8 LOAD_CONST 0 (None) 10 RETURN_VALUE

# code removed by the compiler $ python3 -O x.py 2 0 LOAD_CONST 0 (None) 2 RETURN_VALUE

Victor

Le mer. 21 oct. 2020 à 14:21, Marco Sulla Marco.Sulla.Python@gmail.com a écrit :

If not already present, do you think it's useful to add a macro that does something like

# ifdef Py_DEBUG fprintf(stderr, "%s\n", message); # endif

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