Add get_cell() and get_cells() methods to PartialRowData

[zakons]

Simple method to get a cell value. If no index supplied, get the most recent value.

[googlebot]

Thanks for your pull request. It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

📝 Please visit https://cla.developers.google.com/ to sign.

Once you've signed, please reply here (e.g. I signed it!) and we'll verify. Thanks.

---

• If you've already signed a CLA, it's possible we don't have your GitHub username or you're using a different email address. Check your existing CLA data and verify that your email is set on your git commits.
• If your company signed a CLA, they designated a Point of Contact who decides which employees are authorized to participate. You may need to contact the Point of Contact for your company and ask to be added to the group of authorized contributors. If you don't know who your Point of Contact is, direct the project maintainer to go/cla#troubleshoot.
• In order to pass this check, please resolve this problem and have the pull request author add another comment and the bot will run again.

[zakons]

Signed the CLA!

[googlebot]

We found a Contributor License Agreement for you (the sender of this pull request), but were unable to find agreements for the commit author(s). If you authored these, maybe you used a different email address in the git commits than was used to sign the CLA (login here to double check)? If these were authored by someone else, then they will need to sign a CLA as well, and confirm that they're okay with these being contributed to Google.
In order to pass this check, please resolve this problem and have the pull request author add another comment and the bot will run again.

[zakons]

Added an additional email address for CLA.

[googlebot]

CLAs look good, thanks!

[chemelnucfin]

Thank you for your contribution. We require corresponding tests when you change source code. I was working on something similar and was trying to figure out the unit test but I had the system test working if you want to compare.

Also, @dhermes maybe value would be good enough for the function name?

[chemelnucfin]

@dhermes I think it LGTM to me after my comments, but I'd like you to look it over.

[googlebot]

So there's good news and bad news.

👍 The good news is that everyone that needs to sign a CLA (the pull request submitter and all commit authors) have done so. Everything is all good there.

😕 The bad news is that it appears that one or more commits were authored by someone other than the pull request submitter. We need to confirm that all authors are ok with their commits being contributed to this project. Please have them confirm that here in the pull request.

Note to project maintainer: This is a terminal state, meaning the cla/google commit status will not change from this State. It's up to you to confirm consent of the commit author(s) and merge this pull request when appropriate.

[zakons]

Sorry, this is moving back to using a getters and setters model in Python, which has been repudiated by Guido - see the following thread - https://stackoverflow.com/questions/2579840/do-you-use-the-get-set-pattern-in-python.

The BT API is no exception and will continue to look un-Pythonic to the community if the getter / setter pattern is not eliminated.

Also, we have done extensive performance profiling of the BT API and the single-most contributor to poor performance was this deepcopy() method. As soon as this was eliminated, we got exponential improvements in performance. The cell_valueI() method I added does not expose the Cell to mutability issues since only the value is returned, which is itself immutable.

If a range of cell values (time series) is required, I would add another method to iterate over the cell values, returning in the iterator: index, timestamp, value, which are each immutable.

So the only additional value added in this refactoring is possibly the validity checking of column_family, column, and index - but I would like to know if this is not automatically provided by the underlying Python collections.

Sorry, but until deepcopy's of Cell's are removed from this API, this will continue to be a performance stumbling block to first-time API users, as it was to us. For data science (i.e. BigTable), this is unacceptable and should be removed.

[sduskis]

What do we need to move this forward?

[zakons]

I will take some steps over the weekend to move this forward, now that the row iterator is merged. On Friday, January 26, 2018, 8:55:03 AM EST, Solomon Duskis <notifications@github.com> wrote: What do we need to move this forward? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub, or mute the thread.

[zakons]

Superseded by PR #4908.