For example, from a random image on my machine:

$ docker inspect 67ec76d9f73b | jq '.[] | .Config'
{
  "Hostname": "",
  "Domainname": "",
  "User": "",
  "AttachStdin": false,
  "AttachStdout": false,
  "AttachStderr": false,
  "Tty": false,
  "OpenStdin": false,
  "StdinOnce": false,
  "Env": [
    "PATH=/usr/local/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
    "LANG=C.UTF-8",
    "GPG_KEY=E3FF2839C048B25C084DEBE9B26995E310250568",
    "PYTHON_VERSION=3.8.12",
    "PYTHON_PIP_VERSION=21.2.4",
    "PYTHON_SETUPTOOLS_VERSION=57.5.0",
    "PYTHON_GET_PIP_URL=<https://github.com/pypa/get-pip/raw/3cb8888cc2869620f57d5d2da64da38f516078c7/public/get-pip.py>",
    "PYTHON_GET_PIP_SHA256=c518250e91a70d7b20cceb15272209a4ded2a0c263ae5776f129e0d9b5674309"
  ],
  "Cmd": [
    "python3"
  ],
  "Image": "sha256:525b7bd065f75bf886e56e4662057daddd43ba6955a85cf3540a82e86baffc69",
  "Volumes": null,
  "WorkingDir": "",
  "Entrypoint": null,
  "OnBuild": null,
  "Labels": null
}

I could use that

PATH

to find the

python3

Cmd

for example.