Using Ubuntu 16.04 with Python 3.5 I get import errors for some packages, e.g. 'BeautifulSoup4' or 'requests'. Both libraries are installed from the Ubuntu repositories:
$ dpkg --get-selections | grep -E "python3-req|python3-bs"
Yet I get "ImportError: no module named 'bs4'/'requests'".
$ python3 -c "import bs4"
Traceback (most recent call last):
File "<string>", line 1, in <module>
ImportError: No module named 'bs4'
Only when I (additionally!) install those libraries via pip3 it works. The documentation of BeautifulSoup says to install it as "python3-bs4" via apt. Why does it only work with the pip3 method? What's the purpose of the python3-bs4/python3-requests packages?