Show Kubernetes context in Powerline segment (need kubernetes-py)

kubecontext.py

# -*- coding: utf-8 -*-

# I made it because below related libraries doesn't work with python 3.7.
#
# - https://github.com/zcmarine/powerkube
# - https://github.com/so0k/powerline-kubernetes
#
# NOTE: I don't understand completely how to use powerline watcher.

from kubernetes_py import K8sConfig
from powerline.theme import requires_filesystem_watcher
from os.path import expanduser

watcher = None
context = ''
namespace = ''


@requires_filesystem_watcher
def kubernetes(pl, create_watcher):
    global watcher, context, namespace
    if watcher is None:
        watcher = create_watcher()
        config = K8sConfig()
        context = config.current_context
        namespace = config.namespace
    elif watcher("{0}/.kube/config".format(expanduser("~"))):
        config = K8sConfig()
        context = config.current_context
        namespace = config.namespace

    return [{
        'contents': '{}/{}'.format(context, namespace),
        'highlight_groups': ['information:regular']
    }]