Is there a possibility to execute a Python script while being in interactive mode
import file without the .py extension will do it, however __name__ will not be "__main__" so if the script does any checks to see if it's being run interactively you'll need to bypass them.
Alternately, if you're wanting to have a look at the environment after the script runs try python -i script.py
EDIT: To load it again
file = reload(file)
You might want to look into IPython, a more powerful interactive shell. It has various "magic" commands including %run script.py (which, of course, runs the script and leaves any variables it defined for you to examine).