How to update pip3 sub-version?

Question

I upgraded my Ubuntu server from 15.04 to 16.04 LTS recently. In the process, Python 3.5 was installed. However, the version of pip3 that comes with it apparently wants to use python 3.4 for some reason, not python 3.5.

Here's the error that I see:

-bash: /usr/local/bin/pip3: /usr/bin/python3.4: bad interpreter: No such file or directory

How can I install the appropriate version of pip to work with my python 3.5 install?

Here are the python packages I have installed (found via sudo apt list --installed | grep python):

dh-python/xenial-updates,xenial-updates,now 2.20151103ubuntu1.1 all [installed,automatic]
libpython-stdlib/xenial,now 2.7.11-1 amd64 [installed]
libpython2.7/xenial-updates,xenial-security,now 2.7.12-1ubuntu0~16.04.1 amd64 [installed]
libpython2.7-minimal/xenial-updates,xenial-security,now 2.7.12-1ubuntu0~16.04.1 amd64 [installed]
libpython2.7-stdlib/xenial-updates,xenial-security,now 2.7.12-1ubuntu0~16.04.1 amd64 [installed]
libpython3-stdlib/xenial,now 3.5.1-3 amd64 [installed]
libpython3.5/xenial-updates,xenial-security,now 3.5.2-2ubuntu0~16.04.1 amd64 [installed,automatic]
libpython3.5-minimal/xenial-updates,xenial-security,now 3.5.2-2ubuntu0~16.04.1 amd64 [installed,automatic]
libpython3.5-stdlib/xenial-updates,xenial-security,now 3.5.2-2ubuntu0~16.04.1 amd64 [installed,automatic]
python/xenial,now 2.7.11-1 amd64 [installed]
python-apt/xenial,now 1.1.0~beta1build1 amd64 [installed]
python-apt-common/xenial,xenial,now 1.1.0~beta1build1 all [installed]
python-attr/xenial,xenial,now 15.2.0-1 all [installed,automatic]
python-cffi-backend/xenial,now 1.5.2-1ubuntu1 amd64 [installed,automatic]
python-characteristic/xenial,xenial,now 14.3.0-1 all [installed]
python-chardet/xenial,xenial,now 2.3.0-2 all [installed]
python-configobj/xenial,xenial,now 5.0.6-2 all [installed]
python-cryptography/xenial-updates,xenial-security,now 1.2.3-1ubuntu0.1 amd64 [installed,automatic]
python-debian/xenial,xenial,now 0.1.27ubuntu2 all [installed]
python-enum34/xenial,xenial,now 1.1.2-1 all [installed,automatic]
python-gdbm/xenial,now 2.7.11-2 amd64 [installed]
python-idna/xenial,xenial,now 2.0-3 all [installed]
python-ipaddress/xenial,xenial,now 1.0.16-1 all [installed,automatic]
python-minimal/xenial,now 2.7.11-1 amd64 [installed]
python-openssl/xenial,xenial,now 0.15.1-2build1 all [installed]
python-pam/xenial,now 0.4.2-13.2ubuntu2 amd64 [installed]
python-pkg-resources/xenial,xenial,now 20.7.0-1 all [installed]
python-pyasn1/xenial,xenial,now 0.1.9-1 all [installed]
python-pyasn1-modules/xenial,xenial,now 0.0.7-0.1 all [installed]
python-serial/xenial,xenial,now 3.0.1-1 all [installed]
python-service-identity/xenial,xenial,now 16.0.0-2 all [installed]
python-six/xenial,xenial,now 1.10.0-3 all [installed]
python-twisted-bin/xenial,now 16.0.0-1 amd64 [installed]
python-twisted-core/xenial,xenial,now 16.0.0-1 all [installed]
python-zope.interface/xenial,now 4.1.3-1build1 amd64 [installed]
python2.7/xenial-updates,xenial-security,now 2.7.12-1ubuntu0~16.04.1 amd64 [installed]
python2.7-minimal/xenial-updates,xenial-security,now 2.7.12-1ubuntu0~16.04.1 amd64 [installed]
python3/xenial,now 3.5.1-3 amd64 [installed]
python3-minimal/xenial,now 3.5.1-3 amd64 [installed,automatic]
python3.5/xenial-updates,xenial-security,now 3.5.2-2ubuntu0~16.04.1 amd64 [installed,automatic]
python3.5-minimal/xenial-updates,xenial-security,now 3.5.2-2ubuntu0~16.04.1 amd64 [installed,automatic]

Answer 1

I downloaded the get-pip.py script, and ran it with python3.5. Doing that seemed to clear things up.