Detect if python script is run from an ipython shell, or run from the command line

Question

Is there any way to detect if a python script is being run from an python or ipython shell, or being run from the command line using for example python scrip.py?

I want to use this to set up my matplotlib environment and save or display a figure depending on how the script is run. When I'm running the plotting script from the command line I want the script to use a non-standard matplotlib backend and save the figure to a file with plt.savefig(), but if I'm running it from inside an ipython shell using In [1]: run scrip.py, I want to display the figure using plt.show().

Something like this:

import matplotlib
if run_from_command_line:
    matplotlib.use("non-standard-backend")

import matplotlib.pyplot as plt
if run_from_interactive_shell:
    plt.ion() // Turn on interactive mode in matplotlib

// Do plotting

if run_from_command_line:
    plt.savefig(filename)
else:
    plt.show()

Answer 1

METHOD 1

When running in IPython there is a global variable set called __IPYTHON__. You can just check to see if this exists with:

try:
    __IPYTHON__
except NameError:
    print "Not in IPython"
else:
    print "In IPython"

METHOD 2

As this thread points out you can also look for the get_ipython function in your script to not only check if you are running from IPython, but also to check what configuration IPython has.

METHOD 3

You can also use the inspect module to inspect the stack and find out if you are running from the interactive interpreter etc.

So an example file:

# test.py
import inspect

for frame in inspect.stack():
    print frame

When run from the command line with python test.py the output is:

(<frame object at 0x100378530>, 'test.py', 3, '<module>', ['for frame in inspect.stack():\n'], 0)

When execfile'd from the interactive interpreter:

>>> execfile( "test.py" )
(<frame object at 0x1003795e0>, 'test.py', 3, '<module>', ['for frame in inspect.stack():\n'], 0)
(<frame object at 0x100379430>, '<stdin>', 1, '<module>', None, None)

When run within IPython:

In [1]: %run test
(<frame object at 0x1029002a0>, '/Users/ebarr/Scripts/SO/test.py', 3, '<module>', ['for frame in inspect.stack():\n'], 0)
(<frame object at 0x102900020>, '/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/IPython/utils/py3compat.py', 224, 'execfile', ['            builtin_mod.execfile(filename, *where)\n'], 0)
(<frame object at 0x101d78e20>, '/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/IPython/core/interactiveshell.py', 2537, 'safe_execfile', ['                py3compat.execfile(fname,*where)\n'], 0)
(<frame object at 0x101d78c30>, '/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/IPython/core/magics/execution.py', 703, 'run', ['                                       exit_ignore=exit_ignore)\n'], 0)
(<frame object at 0x101d76390>, '/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/IPython/core/magics/execution.py', 717, 'run', ['                            run()\n'], 0)
(<frame object at 0x101d61760>, '/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/IPython/core/magic.py', 193, '<lambda>', ['        call = lambda f, *a, **k: f(*a, **k)\n'], 0)
(<frame object at 0x101d761a0>, '<string>', 2, 'run', None, None)
(<frame object at 0x101d603e0>, '/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/IPython/core/interactiveshell.py', 2126, 'run_line_magic', ['                result = fn(*args,**kwargs)\n'], 0)
(<frame object at 0x101d5f1f0>, '/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/IPython/core/interactiveshell.py', 2205, 'magic', ['        return self.run_line_magic(magic_name, magic_arg_s)\n'], 0)
(<frame object at 0x101d75e40>, '<ipython-input-1-59a1e9768ae2>', 1, '<module>', [u"get_ipython().magic(u'run test')\n"], 0)
(<frame object at 0x101d75990>, '/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/IPython/core/interactiveshell.py', 2883, 'run_code', ['                exec(code_obj, self.user_global_ns, self.user_ns)\n'], 0)
(<frame object at 0x101d75760>, '/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/IPython/core/interactiveshell.py', 2833, 'run_ast_nodes', ['                if self.run_code(code):\n'], 0)
(<frame object at 0x101d71950>, '/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/IPython/core/interactiveshell.py', 2741, 'run_cell', ['                                   interactivity=interactivity, compiler=compiler)\n'], 0)
(<frame object at 0x101d6ce10>, '/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/IPython/terminal/interactiveshell.py', 567, 'interact', ['                    self.run_cell(source_raw, store_history=True)\n'], 0)
(<frame object at 0x101d6c870>, '/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/IPython/terminal/interactiveshell.py', 443, 'mainloop', ['                    self.interact(display_banner=display_banner)\n'], 0)
(<frame object at 0x101716d60>, '/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/IPython/terminal/ipapp.py', 371, 'start', ['            self.shell.mainloop()\n'], 0)
(<frame object at 0x1017006f0>, '/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/IPython/config/application.py', 563, 'launch_instance', ['        app.start()\n'], 0)
(<frame object at 0x1014fbdd0>, '/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/IPython/__init__.py', 118, 'start_ipython', ['    return launch_new_instance(argv=argv, **kwargs)\n'], 0)
(<frame object at 0x100378560>, '/Library/Frameworks/Python.framework/Versions/2.7/bin/ipython', 11, '<module>', ['    sys.exit(start_ipython())\n'], 0)