Running ACL removal command from python doesn’t work

Question

I am creating a python script to make Kafka ACL manipulation easier. I am not using zookeeper. I am trying to run this command to remove ACLs from consumer groups:

$KH/kafka-acls.sh --bootstrap-server $BS --command-config $KP --remove --allow-principal User:TEST_CONSUMER --consumer --group TEST_GROUP1.CG --topic TEST_TOPIC.TOPIC 

The command asks for confirmation for each ACL and it works when running it manually. However, if I try to run the same command with a python script, it gives this error:

python3 temp.py
Error encountered while running command. Return code: 1
Output:
 Are you sure you want to remove ACLs:
        (principal=User:TEST_CONSUMER, host=*, operation=DESCRIBE, permissionType=ALLOW)
        (principal=User:TEST_CONSUMER, host=*, operation=READ, permissionType=ALLOW)
 from resource filter `ResourcePattern(resourceType=TOPIC, name=TEST_TOPIC.TOPIC, patternType=LITERAL)`? (y/n)
Are you sure you want to remove ACLs:
        (principal=User:TEST_CONSUMER, host=*, operation=READ, permissionType=ALLOW)
 from resource filter `ResourcePattern(resourceType=GROUP, name=TEST_GROUP1.CG, patternType=LITERAL)`? (y/n)
Error while executing ACL command: null
java.lang.NullPointerException
        at kafka.admin.AclCommand$.kafka$admin$AclCommand$$confirmAction(AclCommand.scala:480)
        at kafka.admin.AclCommand$AdminClientService.$anonfun$removeAcls$3(AclCommand.scala:131)
        at kafka.admin.AclCommand$AdminClientService.$anonfun$removeAcls$3$adapted(AclCommand.scala:126)
        at scala.collection.IterableOnceOps.foreach(IterableOnce.scala:563)
        at scala.collection.IterableOnceOps.foreach$(IterableOnce.scala:561)
        at scala.collection.AbstractIterable.foreach(Iterable.scala:926)
        at scala.collection.IterableOps$WithFilter.foreach(Iterable.scala:896)
        at kafka.admin.AclCommand$AdminClientService.$anonfun$removeAcls$1(AclCommand.scala:126)
        at kafka.admin.AclCommand$AdminClientService.removeAcls(AclCommand.scala:123)
        at kafka.admin.AclCommand$.main(AclCommand.scala:75)
        at kafka.admin.AclCommand.main(AclCommand.scala)

This is a test script that just executes the command and that gives the mentioned error:

import subprocess

command = "$KH/kafka-acls.sh --bootstrap-server $BS --command-config $KP --remove --allow-principal User:TEST_CONSUMER --consumer --group TEST_GROUP1.CG --topic TEST_TOPIC.TOPIC"

try:
    proc = subprocess.Popen(command, shell=True, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)

    proc.stdin.write('y\n')
    proc.stdin.flush()

    stdout, stderr = proc.communicate()

    print(f"stdout: {stdout}")
    print(f"stderr: {stderr}")

except Exception as e:
    print(f"Command execution failed: {e}")
    sys.exit(1)

What could be the issue? Will appreciate any useful answers!