dpkg-query: package 'python' is not installed and no information is available

Docker image OS version - Ubuntu 20.04.3 LTS.
Python 2.7.18

During our project source code build time getting below errors.

dpkg-query: package \'python\' is not installed and no information is available'
Use dpkg --info (= dpkg-deb --info) to examine archive files.'

Python 2.7.18 already installed, But not sure why dpkg returning not installed.

$ docker exec -it e5f58a8cef4f apt-get update
Fetched 8489 kB in 7s (1293 kB/s)
Reading package lists... Done

$ docker exec -it r5f58a8aef4f apt -f install
Reading package lists... Done
Building dependency tree
Reading state information... Done
0 upgraded, 0 newly installed, 0 to remove and 75 not upgraded.

$ docker exec -it r5f58a8aef4f apt install python-dev
Reading package lists... Done
Building dependency tree
Reading state information... Done
Some packages could not be installed. This may mean that you have
requested an impossible situation or if you are using the unstable
distribution that some required packages have not yet been created
or been moved out of Incoming.
The following information may help to resolve the situation:

The following packages have unmet dependencies:
 python-dev : Depends: python (= 2.7.11-1)
E: Unable to correct problems, you have held broken packages.

$ docker exec -it r5f58a8aef4f apt policy python
python:
  Installed: (none)
  Candidate: 2.7.11-1
  Version table:
     2.7.11-1 500
        500 http://dk.archive.ubuntu.com/ubuntu xenial/main amd64 Packages

Please suggest a solution.