I tried to install readchar via sudo pip install readchar on my Raspberry Pi but I got the following error Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-install-Qsyv9t/readchar/

I tried to use several Raspberry Pi Operating systems from very old ones and the latest one. But independent of the version I use as OS I get the error message and I am not able to install readchar at all.
Images I tried:

• 2021-12-02-raspios-buster-armhf.img
• 2019-09-26-raspbian-buster-full.img
• 2020-02-13-raspbian-buster-full.img
• 2021-10-30-raspios-bullseye-armhf-full.img

Actual used operating system on my Raspberry Pi:
pi@raspberrypi:~ $ cat /etc/os-release PRETTY_NAME="Raspbian GNU/Linux 10 (buster)" NAME="Raspbian GNU/Linux" VERSION_ID="10" VERSION="10 (buster)" VERSION_CODENAME=buster ID=raspbian ID_LIKE=debian HOME_URL="http://www.raspbian.org/" SUPPORT_URL="http://www.raspbian.org/RaspbianForums" BUG_REPORT_URL="http://www.raspbian.org/RaspbianBugs"

Error message:
pi@raspberrypi:~ $ sudo pip install readchar
Looking in indexes: https://pypi.org/simple, https://www.piwheels.org/simple
Collecting readchar
Using cached https://files.pythonhosted.org/packages/16/2b/0cd0ba53d6dcdc4d69dcff68970c9b1347cc1d7f1c17ed4c15ec3a71a6e5/readchar-3.0.4.tar.gz
Complete output from command python setup.py egg_info:
Traceback (most recent call last):
File "", line 1, in
File "/tmp/pip-install-Qsyv9t/readchar/setup.py", line 85, in
"flake8",
File "/usr/lib/python2.7/dist-packages/setuptools/init.py", line 144, in setup
_install_setup_requires(attrs)
File "/usr/lib/python2.7/dist-packages/setuptools/init.py", line 139, in _install_setup_requires
dist.fetch_build_eggs(dist.setup_requires)
File "/usr/lib/python2.7/dist-packages/setuptools/dist.py", line 724, in fetch_build_eggs
replace_conflicting=True,
File "/usr/lib/python2.7/dist-packages/pkg_resources/init.py", line 782, in resolve
replace_conflicting=replace_conflicting
File "/usr/lib/python2.7/dist-packages/pkg_resources/init.py", line 1065, in best_match
return self.obtain(req, installer)
File "/usr/lib/python2.7/dist-packages/pkg_resources/init.py", line 1077, in obtain
return installer(requirement)
File "/usr/lib/python2.7/dist-packages/setuptools/dist.py", line 791, in fetch_build_egg
return cmd.easy_install(req)
File "/usr/lib/python2.7/dist-packages/setuptools/command/easy_install.py", line 704, in easy_install
return self.install_item(spec, dist.location, tmpdir, deps)
File "/usr/lib/python2.7/dist-packages/setuptools/command/easy_install.py", line 730, in install_item
dists = self.install_eggs(spec, download, tmpdir)
File "/usr/lib/python2.7/dist-packages/setuptools/command/easy_install.py", line 915, in install_eggs
return self.build_and_install(setup_script, setup_base)
File "/usr/lib/python2.7/dist-packages/setuptools/command/easy_install.py", line 1183, in build_and_install
self.run_setup(setup_script, setup_base, args)
File "/usr/lib/python2.7/dist-packages/setuptools/command/easy_install.py", line 1169, in run_setup
run_setup(setup_script, args)
File "/usr/lib/python2.7/dist-packages/setuptools/sandbox.py", line 253, in run_setup
raise
File "/usr/lib/python2.7/contextlib.py", line 35, in exit
self.gen.throw(type, value, traceback)
File "/usr/lib/python2.7/dist-packages/setuptools/sandbox.py", line 195, in setup_context
yield
File "/usr/lib/python2.7/contextlib.py", line 35, in exit
self.gen.throw(type, value, traceback)
File "/usr/lib/python2.7/dist-packages/setuptools/sandbox.py", line 166, in save_modules
saved_exc.resume()
File "/usr/lib/python2.7/dist-packages/setuptools/sandbox.py", line 141, in resume
six.reraise(type, exc, self._tb)
File "/usr/lib/python2.7/dist-packages/setuptools/sandbox.py", line 154, in save_modules
yield saved
File "/usr/lib/python2.7/dist-packages/setuptools/sandbox.py", line 195, in setup_context
yield
File "/usr/lib/python2.7/dist-packages/setuptools/sandbox.py", line 250, in run_setup
_execfile(setup_script, ns)
File "/usr/lib/python2.7/dist-packages/setuptools/sandbox.py", line 45, in _execfile
exec(code, globals, locals)
File "/tmp/easy_install-FGr_SR/importlib_metadata-4.2.0/setup.py", line 6, in

  File "/usr/lib/python2.7/dist-packages/setuptools/__init__.py", line 145, in setup
    return distutils.core.setup(**attrs)
  File "/usr/lib/python2.7/distutils/core.py", line 124, in setup
    dist.parse_config_files()
  File "/usr/lib/python2.7/dist-packages/setuptools/dist.py", line 705, in parse_config_files
    ignore_option_errors=ignore_option_errors)
  File "/usr/lib/python2.7/dist-packages/setuptools/config.py", line 115, in parse_configuration
    options.parse()
  File "/usr/lib/python2.7/dist-packages/setuptools/config.py", line 425, in parse
    section_parser_method(section_options)
  File "/usr/lib/python2.7/dist-packages/setuptools/config.py", line 398, in parse_section
    self[name] = value
  File "/usr/lib/python2.7/dist-packages/setuptools/config.py", line 183, in __setitem__
    value = parser(value)
  File "/usr/lib/python2.7/dist-packages/setuptools/config.py", line 574, in _parse_packages
    'find_namespace: directive is unsupported on Python < 3.3')
distutils.errors.DistutilsOptionError: find_namespace: directive is unsupported on Python < 3.3

----------------------------------------

Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-install-Qsyv9t/readchar/

Python version:
pi@raspberrypi:~ $ python --version Python 2.7.16

My speculation:
Maybe the error is thrown by a name spaces problem?

Thank you very much for your support,

Ingmar