Make Python Client robust to existing IPython installations

[JohnPaton]

In the current implementation of Client._is_ipython, the only check performed is a simple attempted import of the IPython package. However, this will fail in the case that the user (or container) has IPython installed, but the command is being executed from the normal Python interpreter.

This PR adds an extra call to IPython.get_ipython, which returns an instance of the running IPython kernel if any, and otherwise None. By raising an ImportError if get_ipython returns None, the existing logic kicks in and Client._is_ipython will return False as expected, whether IPython happens to be installed or not.

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This change is 

[k8s-ci-robot]

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[k8s-ci-robot]

Hi @JohnPaton. Thanks for your PR.

I'm waiting for a kubeflow member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[animeshsingh]

/lgtm
/approve

[Ark-kun]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: animeshsingh, Ark-kun

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[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: animeshsingh, Ark-kun

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• sdk/OWNERS [Ark-kun]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment