Test for which module an object is from rather than which type it is

Question

With isinstance we can check whether something is of a certain type, but how can we test whether an object is a class belonging to a certain module?

Example:

>>> type(root)
<class 'bs4.BeautifulSoup'>

>>> isinstance(root, BeautifulSoup)
True

How to test whether this object "belongs" to the bs4 package?

Note: When I go over the objects in the soup recursively, it starts as a bs4.BeautifulSoup object, but at another level they are bs4.element.Tag nodes. This is why I want to check for originating from this module rather than a particular type.

Justin O Barber · Accepted Answer · 2014-12-07T16:07:30.053

3

If I understand you correctly, you want to know the module of an object. Is that correct? If so, you will want to check the object's __module__ attribute:

>>> from bs4 import BeautifulSoup
>>> BeautifulSoup.__module__     # module of BeautifulSoup
'bs4'

>>> import requests
>>> r = requests.get('http://www.google.com')
>>> soup = BeautifulSoup(r.content)
>>> soup.__module__               # module of a BeautifulSoup object
'bs4'

In light of your comment, you may be after something like this:

>>> soup = BeautifulSoup('<b class="boldest">A bold statement.</b>')
>>> tag = soup.b
>>> tag.__module__                # module of a Tag object
'bs4.element'

edited Dec 07 '14 at 16:07

answered Dec 07 '14 at 15:51

Justin O Barber

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Nice, but I want to check it of the instance (so in this case, `root.__module__`). Thanks, this is it! – PascalVKooten Dec 07 '14 at 15:52
@PascalvKooten So `root.__module__` is what you are looking for? Or am I still misunderstanding you? – Justin O Barber Dec 07 '14 at 15:59
Indeed, `__module__` is the answer. I can now use `root.__module__` to test whether `root` is an object originating from the `bs4` module. – PascalVKooten Dec 07 '14 at 16:01
@PascalvKooten Thanks for confirming. Perfect. I'm glad this works for you. – Justin O Barber Dec 07 '14 at 16:02
The main reason is that when I loop over the objects in the soup, I sometimes get `bs4.element.Tag`, so I can not test in my function whether the object is a BeautifulSoup object, but I have to check for the module. – PascalVKooten Dec 07 '14 at 16:02
@PascalvKooten Ah, I see. I will add this example to my answer above. – Justin O Barber Dec 07 '14 at 16:06

Test for which module an object is from rather than which type it is

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