python -i (interactive environment)

[Joe]

When you run "python -i scriptname.py" after the script completes you left
at the interactive command prompt.

Is there a way to have this occur from a running program?

In other words can I just run scriptname.py (NOT python -i scriptname.py)
and inside of scriptname.py I decide that I want to fall back to the
interactive prompt?

I've searched and so far the only thing I've come up with is to use pdb, but
that is not exactly the same as the interactive prompt.

Is there any way to do it that I have missed?

Thanks.

[Pierre Barbier de Reuille]

Very simple is you're on UNIX ...

You juste have to put at the beginnin of your file :

#!/usr/bin/python -i

And it juste does what you want :)

Pierre

Joe a écrit :

When you run "python -i scriptname.py" after the script completes you left
at the interactive command prompt.

Is there a way to have this occur from a running program?

In other words can I just run scriptname.py (NOT python -i scriptname.py)
and inside of scriptname.py I decide that I want to fall back to the
interactive prompt?

I've searched and so far the only thing I've come up with is to use pdb, but
that is not exactly the same as the interactive prompt.

Is there any way to do it that I have missed?

Thanks.

[Joe]

Hi Pierre,

Thanks for the reply, but I am not on Unix and it even if I was that
solution it does not achieve the desired results.

I want the script to decide whether to fall back to the interactive prompt.
You solution makes it ALWAYS fall back to the interactive prompt.

I want to do something like:

try:
# execute code
except MyExceptionOccu rred, except_msg:
# fall to interactive prompt.

In other words I want to have my program to determine whether the
interactive prompt to be displayed or not.

Thanks!
"Pierre Barbier de Reuille" <pi************ @cirad.fr> wrote in message
news:42******** *************** @news.free.fr.. .

Very simple is you're on UNIX ...

You juste have to put at the beginnin of your file :

#!/usr/bin/python -i

And it juste does what you want :)

Pierre

Joe a écrit :

When you run "python -i scriptname.py" after the script completes you
left at the interactive command prompt.

Is there a way to have this occur from a running program?

In other words can I just run scriptname.py (NOT python -i scriptname.py)
and inside of scriptname.py I decide that I want to fall back to the
interactive prompt?

I've searched and so far the only thing I've come up with is to use pdb,
but that is not exactly the same as the interactive prompt.

Is there any way to do it that I have missed?

Thanks.

[Michael Hoffman]

Joe wrote:

I want the script to decide whether to fall back to the interactive prompt.
You solution makes it ALWAYS fall back to the interactive prompt.

Actually, using sys.exit() means the program can exit even if python -i
is used.

You can use:

import code
code.interact()

which emulates the interactive prompt.
--
Michael Hoffman

[Raymond L. Buvel]

I posted the following a while back. I think this is what you are
looking for.

This can be done fairly easily by creating a module (lets call it
interactive) with the following code in it.
-----------
import sys,os

def debug_exception (type, value, traceback):
# Restore redirected standard I/O
sys.stdin = sys.__stdin__
sys.stdout = sys.__stdout__
sys.stderr = sys.__stderr__

# Kick the interpreter into interactive mode and call the original
# exception handler.
os.environ['PYTHONINSPECT'] = '1'
sys.__excepthoo k__(type, value, traceback)

sys.excepthook = debug_exception
-----------

Now if you import this module and raise an unhandled exception, you will
be in interactive mode. In other words, I think the following script
does what you are asking for.

-----------
import interactive

raise RuntimeError('I nteractive Mode')
-----------

This also has the advantage that if there are no unhandled exceptions in
your script, the script runs and terminates normally.

Enjoy,
Ray Buvel

Joe wrote:

Hi Pierre,

Thanks for the reply, but I am not on Unix and it even if I was that
solution it does not achieve the desired results.

I want the script to decide whether to fall back to the interactive prompt.
You solution makes it ALWAYS fall back to the interactive prompt.

I want to do something like:

try:
# execute code
except MyExceptionOccu rred, except_msg:
# fall to interactive prompt.

In other words I want to have my program to determine whether the
interactive prompt to be displayed or not.

Thanks!
"Pierre Barbier de Reuille" <pi************ @cirad.fr> wrote in message
news:42******** *************** @news.free.fr.. .

Very simple is you're on UNIX ...

You juste have to put at the beginnin of your file :

#!/usr/bin/python -i

And it juste does what you want :)

Pierre

Joe a écrit :

When you run "python -i scriptname.py" after the script completes you
left at the interactive command prompt.

Is there a way to have this occur from a running program?

In other words can I just run scriptname.py (NOT python -i scriptname.py)
and inside of scriptname.py I decide that I want to fall back to the
interactiv e prompt?

I've searched and so far the only thing I've come up with is to use pdb,
but that is not exactly the same as the interactive prompt.

Is there any way to do it that I have missed?

Thanks.

[MikeyG]

Joe wrote:

When you run "python -i scriptname.py" after the script completes you left
at the interactive command prompt.

Is there a way to have this occur from a running program?

In other words can I just run scriptname.py (NOT python -i scriptname.py)
and inside of scriptname.py I decide that I want to fall back to the
interactive prompt?

I've searched and so far the only thing I've come up with is to use pdb, but
that is not exactly the same as the interactive prompt.

Is there any way to do it that I have missed?

Thanks.

Yes you can set the PYTHONINSPECT environment variable to something
other than an empty string from within your program.

MikeG

[Joe]

Thanks Michael, that's what I was looking for.

Are there any differences between that and the actual interactve prompt that
I should be aware of?

Would you consider that a better method than using (thanks to those who
suggested this other option):

import os
os.environ['PYTHONINSPECT'] = '1'
"Michael Hoffman" <ca*******@mh39 1.invalid> wrote in message
news:d0******** **@gemini.csx.c am.ac.uk...

Joe wrote:

I want the script to decide whether to fall back to the interactive
prompt. You solution makes it ALWAYS fall back to the interactive prompt.

Actually, using sys.exit() means the program can exit even if python -i
is used.

You can use:

import code
code.interact()

which emulates the interactive prompt.
--
Michael Hoffman

[Michael Hoffman]

Joe wrote:

Are there any differences between that and the actual interactve prompt that
I should be aware of?
I don't know, unfortunately.
Would you consider that a better method than using (thanks to those who
suggested this other option):

import os
os.environ['PYTHONINSPECT'] = '1'

Actually I would do that everyone else suggested for your use case. I thought
about trying this method but couldn't imagine that it would actually work!
--
Michael Hoffman

[Joe]

Funny you said that, because I didn't even bother trying it because I didn't
think it would work either. I figured that python did something internally
when it saw the -i switch. Looks like it just checks for it when it's done
with your code.

One difference between the two methods that I see is that when you set
PYTHONINSPECT you don't really have to do anything else and unless
sys.exit() or raise SystemExit is used you will get the interactive prompt.

Using code.interact you would need to wrap everything in a try/except block
and call code.interact from there, or you could invoke it whenever you
wanted too. This has the advantage that you can even trap SystemExit if you
want too.

Thanks again to everyone!
"Michael Hoffman" <ca*******@mh39 1.invalid> wrote in message
news:d0******** **@gemini.csx.c am.ac.uk...

Joe wrote:

Actually I would do that everyone else suggested for your use case. I
thought
about trying this method but couldn't imagine that it would actually work!
--
Michael Hoffman

[Reinhold Birkenfeld]

Michael Hoffman wrote:

Joe wrote:

Are there any differences between that and the actual interactve prompt that
I should be aware of?

I don't know, unfortunately.

Would you consider that a better method than using (thanks to those who
suggested this other option):

import os
os.environ['PYTHONINSPECT'] = '1'

Actually I would do that everyone else suggested for your use case. I thought
about trying this method but couldn't imagine that it would actually work!

Actually, using this behavior is encouraged by the developers. See this
comment in Modules/main.c:

/* Check this environment variable at the end, to give programs the
* opportunity to set it from Python.
*/

Reinhold