Yes. The code started as being indented by tabs, so changing it now is a mess. Also, not to start a flamewar, but I've always preferred tabs to spaces in any language, I find them more reliable, easier to use...
Not going to argue about your personal preference, but in Python spaces for indentation isn't just a personal preference - you'll run into a fair amount of issues with that, this one being just the tip of the iceberg.
Apart from isort not knowing how to deal with tabs, and changing the defaults "spaces" to "tabs" in the tools (along with line length too, because for some reason the 80 character limit is set in stone even though it's absolutely outdated) I haven't had many issues. And this has been running for years already.
The key to success with tabs in any language is simple: Don't use alignment.
Instead, only use indentation.
It is interesting to note that Black-formatted code uses indentation only and never uses alignment. It would be perfectly compatible with tabs, unlike Google-formatted code which relies heavily on column alignment.
If your import statements are indented, they must be in control statements (try/except or conditional imports, I fail to see why you would put those in a loop) thus they will be difficult to reorder if you import another module (with different name or stdlib status) on import error.
What do you mean by this? Are you indenting Python with tabs?