get-pip.py fails with `ModuleNotFoundError: No module named 'dataclasses'`

Question

When running get-pip.py on Python 3.6, I get a failure due to being unable to import dataclasses:

$ python get-pip.py
Traceback (most recent call last):
  File "get-pip.py", line 32710, in <module>
    main()
  File "get-pip.py", line 139, in main
    bootstrap(tmpdir=tmpdir)
  File "get-pip.py", line 115, in bootstrap
    monkeypatch_for_cert(tmpdir)
  File "get-pip.py", line 96, in monkeypatch_for_cert
    from pip._internal.commands.install import InstallCommand
  File "/tmp/tmpvq5rjaoc/pip.zip/pip/_internal/commands/__init__.py", line 9, in <module>
  File "/tmp/tmpvq5rjaoc/pip.zip/pip/_internal/cli/base_command.py", line 13, in <module>
  File "/tmp/tmpvq5rjaoc/pip.zip/pip/_internal/cli/cmdoptions.py", line 23, in <module>
  File "/tmp/tmpvq5rjaoc/pip.zip/pip/_internal/cli/parser.py", line 12, in <module>
  File "/tmp/tmpvq5rjaoc/pip.zip/pip/_internal/configuration.py", line 20, in <module>
  File "/tmp/tmpvq5rjaoc/pip.zip/pip/_internal/exceptions.py", line 14, in <module>
  File "/tmp/tmpvq5rjaoc/pip.zip/pip/_vendor/rich/console.py", line 7, in <module>
ModuleNotFoundError: No module named 'dataclasses'

Answer 1

You have likely used the file at https://bootstrap.pypa.io/get-pip.py, which is no longer compatible with Python 3.6 -- since the latest pip release no longer supports Python 3.6.

You should be able to use https://bootstrap.pypa.io/pip/3.6/get-pip.py instead, which uses a version compatible with Python 3.6.