Before fix
============

root@sonic-10429:/home/admin# docker exec -it pmon bash
root@sonic-10429:/# python3
Python 3.7.3 (default, Jan 22 2021, 20:04:44)
[GCC 8.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from sonic_platform.platform import Platform
>>> c = Platform().get_chassis()
/bin/sh: 1: bcmcmd: not found
>>> 

After fix
===========

root@sonic-10429:/home/admin# docker exec -it pmon bash
root@sonic-10429:/# python3
Python 3.7.3 (default, Jan 22 2021, 20:04:44)
[GCC 8.3.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> from sonic_platform.platform import Platform
>>> c = Platform().get_chassis()
>>>