pip install on Python 2 fails with SyntaxError: sys.stderr.write(f"ERROR: {exc}")

[frimpz]

Traceback (most recent call last):
File "/usr/local/bin/pip", line 9, in
load_entry_point('pip==21.0', 'console_scripts', 'pip')()
File "/usr/local/lib/python2.7/site-packages/pkg_resources.py", line 339, in load_entry_point
return get_distribution(dist).load_entry_point(group, name)
File "/usr/local/lib/python2.7/site-packages/pkg_resources.py", line 2470, in load_entry_point
return ep.load()
File "/usr/local/lib/python2.7/site-packages/pkg_resources.py", line 2184, in load
['name'])
File "/usr/local/lib/python2.7/site-packages/pip/_internal/cli/main.py", line 60
sys.stderr.write(f"ERROR: {exc}")

[jaszhang]

Got the same issue

[frimpz]

Yh but pip install pip==20.3.3 does not give this problem.

I guess the problem is with the new release v21.0, which is on (2021-01-23).

[miketimofeev]

Same here with python 3.5.2. Even pip3 --version gives the error

Traceback (most recent call last):
  File "/usr/bin/pip3", line 11, in <module>
    sys.exit(main())
  File "/home/vsts/.local/lib/python3.5/site-packages/pip/__init__.py", line 16, in main
    from pip._internal.utils.entrypoints import _wrapper
  File "/home/vsts/.local/lib/python3.5/site-packages/pip/_internal/utils/entrypoints.py", line 3, in <module>
    from pip._internal.cli.main import main
  File "/home/vsts/.local/lib/python3.5/site-packages/pip/_internal/cli/main.py", line 60
    sys.stderr.write(f"ERROR: {exc}")
                                   ^
SyntaxError: invalid syntax

[cainmagi]

It is annoying that the new str format f"" only supports python>=3.6. I recommend users who are using python 3.5 to use the following script instead:
https://bootstrap.pypa.io/3.4/get-pip.py
It only supports pip19.1.1.

For users who are using python 2.7, this is a better solution:
https://bootstrap.pypa.io/2.7/get-pip.py
It supports pip20.3.4.

I am not sure whether the latter version supports python3.5. I think it supposes to work.

---

Confirmed, currently
https://bootstrap.pypa.io/2.7/get-pip.py
works on python3.5.

Edited on 1/14/2021

[pradyunsg]

Users of aws-quickstart: please see #9501.

pip 21.0 dropped support for Python 2.7 and Python 3.5. We also dropped support for the same in get-pip.py. As @cainmagi noted, users of Python 2 are expected to use https://bootstrap.pypa.io/2.7/get-pip.py going forward. There's an open issue for adding a corresponding Python 3.5 compatible script too, which would basically be the same as the 2.7 compatible one: pypa/get-pip#83

[crazymind1337]

Same here on Ubuntu 16.04 with pyenv:

./pip3 --version
Traceback (most recent call last):
  File "./pip3", line 7, in <module>
    from pip._internal.cli.main import main
  File "/opt/check-docker/lib/python3.5/site-packages/pip/_internal/cli/main.py", line 60
    sys.stderr.write(f"ERROR: {exc}")

[MauriceHendrix]

I noticed the same issue with python 3.5. It works fine when upgrading the system pip, but if I try it in a virtual environment it tries to install pip 21.0 (whih requires python >= 3.6).

-- Found PythonInterp: /usr/bin/python3.5 (found suitable version "3.5.2", minimum required is "3.5") 
-- Updating pip setuptools and wheel
Collecting pip
  Downloading https://files.pythonhosted.org/packages/de/47/58b9f3e6f611dfd17fb8bd9ed3e6f93b7ee662fb85bdfee3565e8979ddf7/pip-21.0-py3-none-any.whl (1.5MB)
Collecting setuptools
  Downloading https://files.pythonhosted.org/packages/f7/30/f963996d7efea5a336455a3c727711469280c318e2711e295007dea04d7e/setuptools-52.0.0-py3-none-any.whl (784kB)
Collecting wheel
  Downloading https://files.pythonhosted.org/packages/65/63/39d04c74222770ed1589c0eaba06c05891801219272420b40311cd60c880/wheel-0.36.2-py2.py3-none-any.whl
Installing collected packages: pip, setuptools, wheel
  Found existing installation: pip 8.1.1
    Uninstalling pip-8.1.1:
      Successfully uninstalled pip-8.1.1
  Found existing installation: setuptools 20.7.0
    Uninstalling setuptools-20.7.0:
      Successfully uninstalled setuptools-20.7.0
Successfully installed pip-21.0 setuptools-52.0.0 wheel-0.36.2
-- Installing chaste_codegen
Traceback (most recent call last):
  File "/usr/lib/python3.5/runpy.py", line 184, in _run_module_as_main
    "__main__", mod_spec)
  File "/usr/lib/python3.5/runpy.py", line 85, in _run_code
    exec(code, run_globals)
  File "/var/lib/buildbot/slaves/slave/Continuous_Clang_Tidy/build/Debug_develop/codegen_python3_venv/lib/python3.5/site-packages/pip/__main__.py", line 21, in <module>
    from pip._internal.cli.main import main as _main
  File "/var/lib/buildbot/slaves/slave/Continuous_Clang_Tidy/build/Debug_develop/codegen_python3_venv/lib/python3.5/site-packages/pip/_internal/cli/main.py", line 60
    sys.stderr.write(f"ERROR: {exc}")
                                   ^
SyntaxError: invalid syntax

If I specify a specific version it works but I get a message about a newer pip being available:

Successfully installed pip-20.3.4
You are using pip version 20.3.4, however version 21.0 is available.
You should consider upgrading via the 'pip install --upgrade pip' command.
DEPRECATION: Python 3.5 reached the end of its life on September 13th, 2020. Please upgrade your Python as Python 3.5 is no longer maintained. pip 21.0 will drop support for Python 3.5 in January 2021. pip 21.0 will remove support for this functionality.

[adamdavis40208]

a python version check and a friendly error message is much preferred to

  File "/usr/lib/python2.7/site-packages/pip/_internal/cli/main.py", line 60
    sys.stderr.write(f"ERROR: {exc}")

Just an FYI, it took us a few minutes longer to debug than a helpful error message