Agfdhyk

Default python3 on Ubuntu 14.04 is of 3.4.3 but I want to use 3.6.3 instead.

I followed commands below to install 3.6.3:

$ sudo apt-get update

$ sudo apt-get install build-essential libpq-dev libssl-dev openssl libffi-dev zlib1g-dev

$ sudo apt-get install python3-pip python3-dev



$ sudo add-apt-repository ppa:jonathonf/python-3.6

$ sudo apt-get update

$ sudo apt-get install python3.6

3.6.3 was then available on my Ubuntu:

$ which python3.6

/usr/bin/python3.6

For sure, python3 was still pointing to 3.4.3:

$ ls -la /usr/bin/python3

/usr/bin/python3 -> /usr/bin/python3.4

pip3 was available but it used 3.4.3 instead of 3.6.3 (what I wanted):

$ pip3 --version

pip 1.5.4 from /usr/lib/python3/dist-packages (python 3.4)

I thought updating /usr/bin/python3 would solve the issue so I did adjusting the python3 symbolic link making it point to 3.6.3:

$ sudo unlink /usr/bin/python3

$ sudo ln -s /usr/bin/python3.6 /usr/bin/python3

$ ls -la /usr/bin/python3

/usr/bin/python3 -> /usr/bin/python3.6

But pip3 didn't work anymore :(

$ pip3 --version

Traceback (most recent call last):

  File "/usr/bin/pip3", line 5, in <module>

    from pkg_resources import load_entry_point

  File "/usr/lib/python3/dist-packages/pkg_resources.py", line 1479, in <module>

    register_loader_type(importlib_bootstrap.SourceFileLoader, DefaultProvider)

AttributeError: module 'importlib._bootstrap' has no attribute 'SourceFileLoader'

Error in sys.excepthook:

Traceback (most recent call last):

  File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 63, in apport_excepthook

    from apport.fileutils import likely_packaged, get_recent_crashes

  File "/usr/lib/python3/dist-packages/apport/__init__.py", line 5, in <module>

    from apport.report import Report

  File "/usr/lib/python3/dist-packages/apport/report.py", line 30, in <module>

    import apport.fileutils

  File "/usr/lib/python3/dist-packages/apport/fileutils.py", line 23, in <module>

    from apport.packaging_impl import impl as packaging

  File "/usr/lib/python3/dist-packages/apport/packaging_impl.py", line 20, in <module>

    import apt

  File "/usr/lib/python3/dist-packages/apt/__init__.py", line 23, in <module>

    import apt_pkg

ModuleNotFoundError: No module named 'apt_pkg'



Original exception was:

Traceback (most recent call last):

  File "/usr/bin/pip3", line 5, in <module>

    from pkg_resources import load_entry_point

  File "/usr/lib/python3/dist-packages/pkg_resources.py", line 1479, in <module>

    register_loader_type(importlib_bootstrap.SourceFileLoader, DefaultProvider)

AttributeError: module 'importlib._bootstrap' has no attribute 'SourceFileLoader'

UPDATED

I tried with some suggestions:

$ sudo python3.6 -m pip

and

$ curl https://bootstrap.pypa.io/get-pip.py | sudo -H python3.6

But it showed very similar output:

Traceback (most recent call last):

  File "/usr/lib/python3.6/runpy.py", line 183, in _run_module_as_main

    mod_name, mod_spec, code = _get_module_details(mod_name, _Error)

  File "/usr/lib/python3.6/runpy.py", line 142, in _get_module_details

    return _get_module_details(pkg_main_name, error)

  File "/usr/lib/python3.6/runpy.py", line 109, in _get_module_details

    __import__(pkg_name)

  File "/usr/lib/python3/dist-packages/pip/__init__.py", line 59, in <module>

    from pip.log import logger

  File "/usr/lib/python3/dist-packages/pip/log.py", line 9, in <module>

    import colorama, pkg_resources

  File "<frozen importlib._bootstrap>", line 971, in _find_and_load

  File "<frozen importlib._bootstrap>", line 955, in _find_and_load_unlocked

  File "<frozen importlib._bootstrap>", line 656, in _load_unlocked

  File "<frozen importlib._bootstrap>", line 626, in _load_backward_compatible

  File "/usr/share/python-wheels/setuptools-3.3-py2.py3-none-any.whl/pkg_resources.py", line 1479, in <module>

    register_loader_type(importlib_bootstrap.SourceFileLoader, DefaultProvider)

AttributeError: module 'importlib._bootstrap' has no attribute 'SourceFileLoader'

Error in sys.excepthook:

Traceback (most recent call last):

  File "/usr/lib/python3/dist-packages/apport_python_hook.py", line 63, in apport_excepthook

    from apport.fileutils import likely_packaged, get_recent_crashes

  File "/usr/lib/python3/dist-packages/apport/__init__.py", line 5, in <module>

    from apport.report import Report

  File "/usr/lib/python3/dist-packages/apport/report.py", line 30, in <module>

    import apport.fileutils

  File "/usr/lib/python3/dist-packages/apport/fileutils.py", line 23, in <module>

    from apport.packaging_impl import impl as packaging

  File "/usr/lib/python3/dist-packages/apport/packaging_impl.py", line 20, in <module>

    import apt

  File "/usr/lib/python3/dist-packages/apt/__init__.py", line 23, in <module>

    import apt_pkg

How can I solve the issue?

Hi the real problem is described here: https://stackoverflow.com/a/41722610/7933710
TLDR: Using a ppa on older Ubuntu systems is not consistent.

To repair your system you'll have to remove python3.6:

apt-get remove --purge python3.6

add-apt-repository -r ppa:jonathonf/python-3.6

Then download the source and build from source and prepare the system for building:

wget https://www.python.org/ftp/python/3.6.7/Python-3.6.7.tgz

Now prep the system for building:

apt-get install -y make build-essential libssl-dev zlib1g-dev libbz2-dev libreadline-dev libsqlite3-dev wget curl llvm libncurses5-dev  libncursesw5-dev xz-utils tk-dev

All these steps are from the guide here https://realpython.com/installing-python/#compiling-python-from-source

Now configure, make, make altinstall (important)

tar xvf Python-3.6.7.tgz

cd Python-3.6.7/

./configure --enable-optimizations --with-ensurepip=install

make -j 8

make altinstall

The -j 8 means run on 8 cores. Of course if you have less then use the appropriate number. It will not cause a crash in any case.

Now verify the install by runnning

python3.6 -V

which python3.6

Copy the path of python3.6, it should be either /usr/bin/python3.6 or /usr/local/bin/python3.6

You can now use the update-alternatives to manage all python versions on your machine

ls /usr/bin/python*  # e.g. /usr/bin/python2.7 /usr/bin/python3.4 /usr/bin/python3.6

update-alternatives --install /usr/bin/python python /usr/bin/python2.7 1

update-alternatives --install /usr/bin/python python /usr/bin/python3.4 1

update-alternatives --install /usr/bin/python python /usr/local/bin/python3.6 2

The number 2 signifies the priority for running python on your machine. In this case 2 > 1, so you'll prefer python3.6. If you want to change to version 3.4 you can just run update-alternatives --config python which is an interactive configurator.

Now you can use python -m pip -V to verify pip is working correctly. You can also use pip3.6 to install packages.