[MRG] f-string updates for issue #29547

[abbiepopa]

Addresses, in part, #29547

…ape/pivot, reshape/reshape

• [ x] xref Replace old string formatting syntax with f-strings #29547
• [n/a ] tests added / passed
• [x ] passes black pandas
• [ x] passes git diff upstream/master -u -- "*.py" | flake8 --diff
• [n/a ] whatsnew entry

[pep8speaks]

Hello @abbiepopa! Thanks for updating this PR. We checked the lines you've touched for PEP 8 issues, and found:

There are currently no PEP 8 issues detected in this Pull Request. Cheers! 🍻

Comment last updated at 2020-02-03 04:07:53 UTC

[WillAyd]

Thanks for the PR! Mostly minor edits

[abbiepopa]

Thank you @WillAyd , I covered the changes you requested. I'm having some trouble figuring out why I'm failing the current tests. LMK if it's obvious to you, otherwise I will continue investigating.

[MarcoGorelli]

Thanks, Abbie!

I'm having some trouble figuring out why I'm failing the current tests

If you click on 'details' next to, say, "CI / Checks", you'll see an 'X' near 'linting'. If you expand it, you'll see

black --version
black, version 19.10b0
Checking black formatting
would reformat /home/runner/work/pandas/pandas/pandas/core/reshape/concat.py
would reformat /home/runner/work/pandas/pandas/pandas/core/reshape/melt.py
would reformat /home/runner/work/pandas/pandas/pandas/core/reshape/pivot.py
would reformat /home/runner/work/pandas/pandas/pandas/core/reshape/merge.py
Oh no! 💥 💔 💥
4 files would be reformatted, 923 files would be left unchanged.

So for a start, you need to run black again any file you've changed. For example,

black pandas/core/reshape/concat.py

The contributing guide has some more info about this.

[abbiepopa]

Thank you, @MarcoGorelli ! Looks like the latest failure is a timeout. Is there a way to retrigger the test that timed out? Never mind, I found some instructions in the contributor wiki, retrying now.

[abbiepopa]

Yay! Thanks @WillAyd and @MarcoGorelli . LMK if you need additional changes etc.

[jreback]

comment, pls ping on green.

[abbiepopa]

Thanks @jreback and @MomIsBestFriend ! I updated based on your reviews.

[WillAyd]

Great thanks @abbiepopa