Arch Linux

Description:

I get this error when running pip:

```
Traceback (most recent call last):
File "/usr/bin/pip", line 11, in <module>
load_entry_point('pip==18.0', 'console_scripts', 'pip')()
File "/usr/lib/python3.7/site-packages/pkg_resources/__init__.py", line 476, in load_entry_point
return get_distribution(dist).load_entry_point(group, name)
File "/usr/lib/python3.7/site-packages/pkg_resources/__init__.py", line 2700, in load_entry_point
return ep.load()
File "/usr/lib/python3.7/site-packages/pkg_resources/__init__.py", line 2318, in load
return self.resolve()
File "/usr/lib/python3.7/site-packages/pkg_resources/__init__.py", line 2324, in resolve
module = __import__(self.module_name, fromlist=['__name__'], level=0)
File "/usr/lib/python3.7/site-packages/pip/_internal/__init__.py", line 42, in <module>
from pip._internal import cmdoptions
File "/usr/lib/python3.7/site-packages/pip/_internal/cmdoptions.py", line 16, in <module>
from pip._internal.index import (
File "/usr/lib/python3.7/site-packages/pip/_internal/index.py", line 24, in <module>
from pip._internal.download import HAS_TLS, is_url, path_to_url, url_to_path
File "/usr/lib/python3.7/site-packages/pip/_internal/download.py", line 47, in <module>
from pip._internal.utils.ui import DownloadProgressProvider
File "/usr/lib/python3.7/site-packages/pip/_internal/utils/ui.py", line 11, in <module>
from pip._vendor.progress.bar import (
ModuleNotFoundError: No module named 'pip._vendor.progress'
```

I've read https://bbs.archlinux.org/viewtopic.php?id=237451 and https://bugs.archlinux.org/task/40713 which had some suggested solutions but nothing worked. For example, just for clarification: `pacman -Qlq python-pip | grep 3.6` prints nothing.

I've checked that my system is fully updated.