python /somewhere/bar.py /somewhere_else/foo.py

import imp
import sys

# Debugging code here

fp, pathname, description = imp.find_module(sys.argv[1])
imp.load_module('__main__', fp, pathname, description)

"This module is automatically imported during initialization."

import imp

import os

if 'MY_STARTUP_FILE' in os.environ:
    try:
        file_path = os.environ['MY_STARTUP_FILE']
        folder, file_name = os.path.split(file_path)
        module_name, _ = os.path.splitext(file_name)
        fp, pathname, description = imp.find_module(module_name, [folder])
    except Exception as e:
        # Broad exception handling since sitecustomize exceptions are ignored
        print "There was a problem finding startup file", file_path
        print repr(e)
        exit()

    try:
        imp.load_module(module_name, fp, pathname, description)
    except Exception as e:
        print "There was a problem loading startup file: ", file_path
        print repr(e)
        exit()
    finally:
        # "the caller is responsible for closing the file argument" from imp docs
        if fp:
            fp.close()

MY_STARTUP_FILE=/somewhere/bar.py python /somewhere_else/foo.py

test|-- foo.py
    |-- bar
         |--bar.py

import sys

a = 1
print ('debugging...')

# run the other file
if sys.argv[1].endswith('.py'): # if .py run right away
    execfile(sys.argv[1], globals(), locals())
elif sys.argv[1].endswith('.pyc'): # if .pyc, first uncompyle, then run
    import uncompyle2
    from StringIO import StringIO
    f = StringIO()
    uncompyle2.uncompyle_file(sys.argv[1], f)
    f.seek(0)
    exec(f.read(), globals(), locals())

print a
print 'real job'

$ python foo.py bar/bar.py
$ python foo.py bar/bar.pyc

debugging...
1
real job

if __name__ == '__main__':
    # some code

if __name__ == '__main__':
    main()

if __name__ == "__main__":
    # You debugging setup goes here
    ...
    # Run the Python program given as argv[1]
    run_script_as_main(sys.argv[1:])

$ find so-foo-bar
so-foo-bar
so-foo-bar/debugaid
so-foo-bar/debugaid/bar.py
so-foo-bar/foo.py

import sys

if __name__ == "__main__":
    print "My name is", __name__
    print "My file is", __file__
    print "My command line is", sys.argv
    print "First 2 path items", sys.path[:2]
    print "Globals", globals().keys()
    raise Exception("foo")

run_script_as_main

export PYTHONPATH=$HOME/dirWithFoo/:$PYTHONPATH

from foo import myfunc

myfunc()

imp.load_source('__main__', '../../foo.py')

#!/usr/bin/env python

import imp
import sys
import os.path

file_path = sys.argv.pop(1)
assert os.path.exists(file_path)

folder, file_name = os.path.split(file_path)

###############################################################################
#                                                                             #

# Debugging cruft here

#                                                                             #
###############################################################################


module_name, _ = os.path.splitext(file_name)
sys.path.append(folder)
imp.load_module('__main__', *imp.find_module(module_name))

python <(cat /somewhere/bar.py /somewhere_else/foo.py)