root~# kubectl exec alpinec1-7c65db48b4-v2gpc -- /bin/sh -c 'ls /'
bin
dev
etc
home
...

from kubernetes import client, config
config.load_kube_config()
v1 = client.CoreV1Api()
exec_command = ['/bin/sh',
                '-c',
                'ls /']
>>> v1.connect_post_namespaced_pod_exec("alpinec1-7c65db48b4-v2gpc", "default", command=exec_command, stderr=False, stdin=False, stdout=True, tty=False)
Traceback (most recent call last):
  File "/home/root/Desktop/pycharm-community-2018.1.4/helpers/pydev/_pydevd_bundle/pydevd_exec2.py", line 3, in Exec
    exec(exp, global_vars, local_vars)
  File "<input>", line 1, in <module>
  File "/root/PycharmProjects/KubeProject1/venv/lib/python3.5/site-packages/kubernetes/client/apis/core_v1_api.py", line 3788, in connect_post_namespaced_pod_exec
    (data) = self.connect_post_namespaced_pod_exec_with_http_info(name, namespace, **kwargs)
  File "/root/PycharmProjects/KubeProject1/venv/lib/python3.5/site-packages/kubernetes/client/apis/core_v1_api.py", line 3888, in connect_post_namespaced_pod_exec_with_http_info
    collection_formats=collection_formats)
  File "/root/PycharmProjects/KubeProject1/venv/lib/python3.5/site-packages/kubernetes/client/api_client.py", line 321, in call_api
    _return_http_data_only, collection_formats, _preload_content, _request_timeout)
  File "/root/PycharmProjects/KubeProject1/venv/lib/python3.5/site-packages/kubernetes/client/api_client.py", line 155, in __call_api
    _request_timeout=_request_timeout)
  File "/root/PycharmProjects/KubeProject1/venv/lib/python3.5/site-packages/kubernetes/client/api_client.py", line 364, in request
    body=body)
  File "/root/PycharmProjects/KubeProject1/venv/lib/python3.5/site-packages/kubernetes/client/rest.py", line 266, in POST
    body=body)
  File "/root/PycharmProjects/KubeProject1/venv/lib/python3.5/site-packages/kubernetes/client/rest.py", line 222, in request
    raise ApiException(http_resp=r)
kubernetes.client.rest.ApiException: (400)
Reason: Bad Request
HTTP response headers: HTTPHeaderDict({'Content-Length': '139', 'Content-Type': 'application/json', 'Date': 'Sun, 22 Jul 2018 14:08:41 GMT'})
HTTP response body: {"kind":"Status","apiVersion":"v1","metadata":{},"status":"Failure","message":"Upgrade request required","reason":"BadRequest","code":400}