Detecting when a python script is being run interactively

Question

Is there a way for a python script to automatically detect whether it is being run interactively or not? Alternatively, can one detect whether ipython is being used versus the regular c python executable?

Background: My python scripts generally have a call to exit() in them. From time to time, I run the scripts interactively for debugging and profiling, usually in ipython. When I'm running interactively, I want to suppress the calls to exit.

Clarification:

Suppose I have a script, myscript.py, that looks like:

#!/usr/bin/python
...do useful stuff...
exit(exit_status)

Sometimes, I want to run the script within an IPython session that I have already started, saying something like:

In [nnn]: %run -p -D myscript.pstats myscript.py

At the end of the script, the exit() call will cause ipython to hang while it asks me if I really want to exit. This is a minor annoyance while debugging (too minor for me to care), but it can mess up profiling results: the exit prompt gets included in the profile results (making the analysis harder if I start a profiling session before going off to lunch).

What I'd like is something that allows me modify my script so it looks like:

#!/usr/bin/python
...do useful stuff...
if is_python_running_interactively():
    print "The exit_status was %d" % (exit_status,)
else:
    exit(exit_status)

Answer 1

When invoked interactively, python will run the script in $PYTHONSTARTUP, so you could simply have that environment variable invoke a script which sets a global

Answer 2

I stumbed on the following and it seems to do the trick for me:

def in_ipython():
    try:
        __IPYTHON__
    except NameError:
        return False
    else:
        return True