[Python-Dev] Re: Activating `-i' from inside a script?

[Skip Montanaro]

On c.l.py someone asked about forcing a tailend interactive shell from
within the program.  Try Melhase proposed:

    import os

    if __name__ == '__main__':
        discrepancy = True
        if discrepancy:
            os.environ['PYTHONINSPECT'] = "why yes, i'd like that"

but observed that it doesn't work because the environment variable is only
checked at program start.

This change to Modules/main.c makes the above work:

% cvs diff main.c
Index: main.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Modules/main.c,v
retrieving revision 1.77
diff -c -r1.77 main.c
*** main.c      30 Mar 2003 17:09:58 -0000      1.77
--- main.c      27 Jun 2003 11:50:42 -0000
***************
*** 418,423 ****
--- 418,428 ----
                        filename != NULL, &cf) != 0;
        }
  
+       /* also check at the end in case the program set PYTHONINSPECT */
+       if (!saw_inspect_flag &&
+           (p = Py_GETENV("PYTHONINSPECT")) && *p != '\0')
+               inspect = 1;
+ 
        if (inspect && stdin_is_interactive &&
            (filename != NULL || command != NULL))
                /* XXX */

I can't see that it would affect the functioning of any programs other than
those which set PYTHONINSPECT now.  (But why would they do that and what's
the likelihood such programs exist?)

Any chance this could be squeezed in?  It seems rather elegant:

    try:
        something which fails
    except:
        os.environ["PYTHONINSPECT"] = 1
        raise

(I know we're at beta1, and the programmer could re-run with -i.  But
still...)

Skip