I must note that I am not an expert in Android development. But I researched on this topic, and @Emile's answer is the easiest and closest you can get - as it seems.

You can actually run Fedora (and not only) image on top of the Termux and then launch Python inside. This is obviously not a docker, but might be helpful.You can find more info here.

In addition, I've found this topic on Quora which is a similar question:

Think about it: Docker abstracts the OS and that is all. The Android OS is quite a different kernel than linux distributions, even though it is linux. It might be tricky to get applications meant for a linux distribution to run on Android/Docker.

One of the main reasons to use docker is that it can provide self-contained packages of applications which do not affect the rest of the system. The Android applications, packaged as .apk files are just that.

Other than that I was able to find this topic on StackOverflow which does not really resolve the issue. As the issue might be related to AUFS and some Kernel features needed by LXT which are not present in Android - now some of them is from what I remember.

Also there is a claim that it is possible on docker forum and weibo (use translation to English), but there is only a screenshot provided by user and no details on how to do it, besides "it took a lot of effort" statement. So it would seam that this is still a not well known part, or maybe someone will be able to actually provide more complementary information - maybe try on Docker forum or GitHub.