Core Python Programming (2nd Edition)

import import2
And here are the contents of import2.py:
# import2.py
print 'loaded import2'
Here is the output when we import import1 from Python:
>>> import import1
loaded import1
loaded import2
>>>
Following our suggested workaround of checking the value of __name__, we can change the code in
import1.py and import2.py so that this behavior does not occur.
Here is the modified version of import1.py:
# import1.py
import import2
if __name__ == '__main__':
print 'loaded import1'
The following is the code for import2.py, changed in the same manner:
# import2.py
if __name__ == '__main__'
print 'loaded import2'
We no longer get any output when we import import1 from Python:
>>>import import1
>>>
Now it does not necessarily mean that this is the behavior you should code for all situations. There may
be cases where you want to display output to confirm a module import. It all depends on your situation.
Our goal is to provide pragmatic programming examples to prevent unintended side effects.
14.4.2. execfile()
It should seem apparent that importing a module is not the preferred method of executing a Python
script from within another Python script; that is not what the importing process is. One side effect of
importing a module is the execution of the top-level code.