Questions[python3](ubuntu)

Having used Ubuntu 18.04 for a handful of years now, and reading that Python 2 has been removed from Ubuntu 20.04, I was looking forward to using the commands python or pip rather than python3 or pip3. So today I tried Ubuntu 20.04 for the first time, and found:

$ python --version

Command 'python' not found

$ python3 --version
Python 3.8.5

I was surprised and upon looking into things further found the following about the package python-is-python3:

https://packages.ubuntu.com/focal/python-is-python3

https://launchpad.net/ubuntu/focal/+package/python-is-python3

How to make 'python' program command execute Python 3?

The middle of these 3 links is the most descriptive, but none are especially clear about what python-is-python3 is/does and the full scope of ramifications if sudo apt-get install python-is-python3 was to be ran on a Ubuntu 20.04 install.

Here are some questions I have about python-is-python3:

1. Is python-is-python3 proprietary to Ubuntu/Canonical? If so, do other Linux distributions use python-is-python3 also or do some other distributions have a similar equivalent?

2. I gather if I was to run python-is-python3 from the command prompt then I could use the command python instead of python3. First can somebody confirm this, and second, does the same go for pip, i.e. pip instead of pip3?

3. The launchpad.net link above mentions creation of a symlink. Does python-is-python3 really just create a single symlink? It seems odd to introduce a package for such a bare bones purpose. Also, if this package is subsequently uninstalled (i.e. sudo apt --purge remove python-is-python3) does this remove the symlink?

4. Are there any commonly used Python 2 packages out there anymore? I can't think of any offhand.

5. Has anybody ran python-is-python3 and then later regretted doing so due to a reason that was not realized ahead of time?

6. It seems the benefit of running python-is-python3 would be not having to add the 3 at the end of Python commands, but the disadvantage is that you would then have a non-standard Ubuntu setup, is this a fair summary of the python-is-python3 benefit/drawback?

After updating to Ubuntu 20.04, whenever I run:

pip install <some package>

or

pip --version

it says:

adam@daryy:~$ pip3

Traceback (most recent call last):
  File "/usr/local/bin/pip3", line 5, in <module>
    from pip._internal.cli.main import main
  File "/usr/local/lib/python3.7/dist-packages/pip/_internal/cli/main.py", line 10, in <module>
    from pip._internal.cli.autocompletion import autocomplete
  File "/usr/local/lib/python3.7/dist-packages/pip/_internal/cli/autocompletion.py", line 9, in <module>
    from pip._internal.cli.main_parser import create_main_parser
  File "/usr/local/lib/python3.7/dist-packages/pip/_internal/cli/main_parser.py", line 7, in <module>
    from pip._internal.cli import cmdoptions
  File "/usr/local/lib/python3.7/dist-packages/pip/_internal/cli/cmdoptions.py", line 19, in <module>
    from distutils.util import strtobool
ModuleNotFoundError: No module named 'distutils.util'
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 23, 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/local/bin/pip3", line 5, in <module>
    from pip._internal.cli.main import main
  File "/usr/local/lib/python3.7/dist-packages/pip/_internal/cli/main.py", line 10, in <module>
    from pip._internal.cli.autocompletion import autocomplete
  File "/usr/local/lib/python3.7/dist-packages/pip/_internal/cli/autocompletion.py", line 9, in <module>
    from pip._internal.cli.main_parser import create_main_parser
  File "/usr/local/lib/python3.7/dist-packages/pip/_internal/cli/main_parser.py", line 7, in <module>
    from pip._internal.cli import cmdoptions
  File "/usr/local/lib/python3.7/dist-packages/pip/_internal/cli/cmdoptions.py", line 19, in <module>
    from distutils.util import strtobool
ModuleNotFoundError: No module named 'distutils.util'

even when I normally type pip3 or pip.

I want to upgrade from Ubuntu 16.04.5 LTS to 18.04, so ran sudo do-release-upgrade. After downloading and extracting bionic.tar.gz I get:

Can not upgrade 

Your python3 install is corrupted. Please fix the '/usr/bin/python3'
symlink.

I saw How to fix "python installation is corrupted"? and so I did sudo ln -sf /usr/bin/python3.6 /usr/bin/python3 thinking that it would be a similar problem. But that didn't work (still same error message).

I have a few python versions:

$ ls /usr/lib | grep python
python2.7
python3
python3.5
python3.6

$ update-alternatives --display python3
python3 - auto mode
  link best version is /usr/bin/python3.6
  link currently points to /usr/bin/python3.6
  link python3 is /usr/bin/python3
/usr/bin/python3.5 - priority 1
/usr/bin/python3.6 - priority 2

How do I fix python3?

I am new to Ubuntu and Linux in general.

I created a dual boot OS on my laptop (Windows 10 and Ubuntu).

• Typing: sudo apt-get install python3-tk (or even python-tk) didn't work.
• Trying to install the python3-dev or python-devel (no luck).
• Downloading Tcl and Tk to manually install.

In Windows 10 Bash Subsystem the Tk and Tcl are already included, so I thought Ubuntu already had it. But, I want to use my Ubuntu desktop to develop Python GUI apps.

So, how can I install the Tcl/Tk to be use in Python 3.5 for GUI development?

I loaded Python 3.5.2 fine but need the GUI modules enabled.

The code to test that Tk is working is:

1. Type python3

2. Type:

   import tkinter   
   tkinter._test()
   

3. Result: a GUI pop-up displaying This is a Tcl/Tk version..

I just finished installing python 3.5.1 on my Ubuntu, but am faced with this error message, regardless if I'm installing with Anaconda or with apt-get:

No module named 'gdbm'

that normally displays on my terminal. I have also tried installing gdbm using:

sudo apt-get install gdbm

but doesn't solve the problem. Can I get a help on how to fix this problem from anyone here?