DockerClient can be used to do something on Docker, such as list, start or stop containers.

Here is the minimal boilerplate code without any error handling to initialize the client.

#!/usr/bin/python3
import docker
client = docker.DockerClient(base_url='unix:///var/run/docker.sock')
print(client)

Or, using TCP.

#!/usr/bin/python3
import docker
client = docker.DockerClient(base_url='tcp://127.0.0.1:1234')
print(client)

Here is a more practical example, with try/except/else error handling.

#!/usr/bin/python3
import docker
import sys

try:
    client = docker.DockerClient(base_url='unix:///var/run/docker.sock')
except Exception as exception:
    print(exception)
else:
    print(client)

If the client is successfully initialized, something like this should be returned.

<docker.client.DockerClient object at 0x7fe584972cd0>

And here is an example of how to list containers using containers.list.

#!/usr/bin/python3
import docker
import sys

try:
    client = docker.DockerClient(base_url='unix:///var/run/docker.sock')
except Exception as exception:
    print(exception)
else:
    print(client)

try:
    containers = client.containers.list(all=True)
except Exception as exception:
    print(exception)
else:
    print(containers)

Something like this should be returned, the ID of each container.

[<Container: d9facc570d98>, <Container: 301cb96aaef0>, <Container: 644cb1728845>, <Container: b2499df7a9fe>, <Container: f00d97c27974>]

Each response will be a class that contains key/value pairs. Here is how you could return the status of the container, such as "running" or "stopped".

#!/usr/bin/python3
import docker
import sys

try:
    client = docker.DockerClient(base_url='unix:///var/run/docker.sock')
except Exception as exception:
    print(exception)
    sys.exit(1)

try:
    containers = client.containers.list(all=True)
except Exception as exception:
    print(exception)
    sys.exit(1)


for container in containers:
    try:
        container.status
    except Exception as exception:
        print(exception)
        sys.exit(1)
    else:
        if container.status != "running":
            print(f"Docker container {container.name}is NOT running")
        else:
            print(f"Docker container {container.name} is running")
sys.exit(0)