How to execute a “hello redis” sample python script on a container from the host?

Question

How do I execute this "Hello Redis!!!" sample from the host?

root@mordor:~# 
root@mordor:~# docker container ls
CONTAINER ID        IMAGE                COMMAND                  CREATED             STATUS              PORTS               NAMES
0d51479c1b57        redislabs/redis-py   "docker-entrypoint.s…"   12 minutes ago      Up 12 minutes       6379/tcp            redis-python
ea782770bcff        redis                "docker-entrypoint.s…"   26 minutes ago      Up 26 minutes       6379/tcp            rd
root@mordor:~# 
root@mordor:~# docker exec -it --user root redis-python bash
root@0d51479c1b57:/usr/src/app# 
root@0d51479c1b57:/usr/src/app# ls
requirements.txt  test_db.py  test_db.py.1
root@0d51479c1b57:/usr/src/app# 
root@0d51479c1b57:/usr/src/app# cat test_db.py.1 
# The MIT License (MIT)
#
# Copyright (c) 2018 Redis Labs
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
# 
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
#
# Script Name: settings.sh
# Author: Cihan Biyikoglu - github:(cihanb)


import sys
import redis

# try:

print (":: test_db.py")

if (len(sys.argv) <= 1):
    print("Need to provide a DB port to test connectiivity. Example: python Redis-Python-Sample.py 12000")

host_name = sys.argv[1]
db_port = sys.argv[2]

print("Connecting to host={0} and port={1}".format(host_name,db_port))
r = redis.StrictRedis(host=host_name, port=db_port, db=0)

print("Set key 'key1' to value '123' on host={0} and port={1}".format(host_name,db_port))
r.set('key1', '123')

print("Get key 'key1' and validate value is '123' on host={0} and port={1}".format(host_name,db_port))
if (r.get('key1') == b'123'):
    print("DB TEST PASSED")
else:
    print("DB TEST FAILED: Can't find the key")

# except:
#     print("DB TEST FAILED")


root@0d51479c1b57:/usr/src/app#  
root@0d51479c1b57:/usr/src/app# cat test_db.py
import sys
import redis

print (":: test_db.py")


    
r = redis.StrictRedis(host="127.0.0.1", port=6379, decode_responses=True)
    
r.set("msg:hello", "Hello Redis!!!")
    
msg = r.get("msg:hello")
    
print(msg)

    
if (r.get('key1') == b'123'):
    print("DB TEST PASSED")
else:
    print("DB TEST FAILED: Can't find the key")
root@0d51479c1b57:/usr/src/app# 
root@0d51479c1b57:/usr/src/app# cat requirements.txt 
redis



root@0d51479c1b57:/usr/src/app# 
root@0d51479c1b57:/usr/src/app# python3 test_db.py
Traceback (most recent call last):
  File "test_db.py", line 2, in <module>
    import redis
ImportError: No module named 'redis'
root@0d51479c1b57:/usr/src/app# 
root@0d51479c1b57:/usr/src/app# pip3 install redis
Downloading/unpacking redis
  Downloading redis-3.5.3-py2.py3-none-any.whl (72kB): 72kB downloaded
Installing collected packages: redis
Successfully installed redis
Cleaning up...
root@0d51479c1b57:/usr/src/app# 
root@0d51479c1b57:/usr/src/app# python3 test_db.py
:: test_db.py
Hello Redis!!!
DB TEST FAILED: Can't find the key
root@0d51479c1b57:/usr/src/app# 

it's fine that the test failed, only concerned about execution.

I dumbed down the script to better work with the default community build of redis.