In a Python script, is there any way to tell if the interpreter is running in interactive mode? This would be useful so that, for instance, when you run an interactive Python session and import a module, different code can be executed.
What I mean is something like this:
if __name__ == "__main__":
# do stuff
elif __pythonIsInteractive__:
# do other stuff
else:
exit()
__main__.__file__ doesn't exist in the interactive interpreter for Python versions <= 3.12:
import __main__
print(hasattr(__main__, "__file__"))
This also goes for code run via python -c, but not python -m.
bool(getattr(sys, 'ps1', sys.flags.interactive)), py2.6+
PYTHONSTARTUP=script.py python3. The expression 'readline' in sys.modules can, as well as python3 -i script.py and python3 -ic 'import script' (tested with Python 3.8.2 on Ubuntu focal), but it's highly non-portable.
ptpython interactive session started via python -m ptpython.I compared all the methods I found and made a table of results. The best one seems to be this:
hasattr(sys, 'ps1')
If anyone has other scenarios that might differ, comment and I'll add it
hasattr(sys, 'ps1') returns False in PyCharm 2022.1.4 (CE) console on Windows 11
hasattr(sys, 'ps1') matched the values in the first row labelled "Expected". The problem with sys.__stdout__.isatty was that it returned True where it shouldn't, like when running a Python file in a shell.
__main__.__file__ is there in Python 3.13 but missing in Python 3.12).
sys.ps1 and sys.ps2 are defined even when iPython is run not in interactive mode.Use sys.flags:
if sys.flags.interactive:
#interactive
else:
#not interactive
From TFM: If no interface option is given, -i is implied, sys.argv[0] is an empty string ("") and the current directory will be added to the start of sys.path.
If the user invoked the interpreter with python and no arguments, as you mentioned, you could test this with if sys.argv[0] == ''. This also returns true if started with python -i, but according to the docs, they're functionally the same.
argv[0] is NULL or an empty string and I don't really feel like debugging any potential errors caused by that...The following works both with and without the -i switch:
#!/usr/bin/python
import sys
# Set the interpreter bool
try:
if sys.ps1: interpreter = True
except AttributeError:
interpreter = False
if sys.flags.interactive: interpreter = True
# Use the interpreter bool
if interpreter: print 'We are in the Interpreter'
else: print 'We are running from the command line'
if sys.ps1: interpreter = True => interpreter = sys.ps1 or interpreter = bool(sys.ps1).
try ... except statement? I only recommended replacing an if with a plain assignment.if also needs the boolean value of sys.ps1.bool(getattr(sys, 'ps1', sys.flags.interactive))Here's something that would work. Put the following code snippet in a file, and assign the path to that file to the PYTHONSTARTUP environment variable.
__pythonIsInteractive__ = None
And then you can use
if __name__=="__main__":
#do stuff
elif '__pythonIsInteractive__' in globals():
#do other stuff
else:
exit()
http://docs.python.org/tutorial/interpreter.html#the-interactive-startup-file
