CLN: replace %s syntax with .format in pandas.io
progress towards #16130

- [x] tests added / passed
- [x] passes `git diff upstream/master -u -- "*.py" | flake8 --diff`

# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24719?src=pr&el=h1) Report
> Merging [#24719](https://codecov.io/gh/pandas-dev/pandas/pull/24719?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/d46d2a5ea900c59439dff58942e79ea8b39e918d?src=pr&el=desc) will **increase** coverage by `<.01%`.
> The diff coverage is `82.08%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/24719/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/24719?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #24719      +/-   ##
==========================================
+ Coverage   92.38%   92.38%   +<.01%     
==========================================
  Files         166      166              
  Lines       52321    52321              
==========================================
+ Hits        48337    48338       +1     
+ Misses       3984     3983       -1
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.8% <25.37%> (ø)` | :arrow_up: |
| #single | `43.06% <80.59%> (-0.01%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/24719?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/io/packers.py](https://codecov.io/gh/pandas-dev/pandas/pull/24719/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL3BhY2tlcnMucHk=) | `88.21% <0%> (ø)` | :arrow_up: |
| [pandas/io/sas/sas7bdat.py](https://codecov.io/gh/pandas-dev/pandas/pull/24719/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL3Nhcy9zYXM3YmRhdC5weQ==) | `91.16% <33.33%> (ø)` | :arrow_up: |
| [pandas/io/pytables.py](https://codecov.io/gh/pandas-dev/pandas/pull/24719/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL3B5dGFibGVzLnB5) | `92.31% <85.71%> (ø)` | :arrow_up: |
| [pandas/util/testing.py](https://codecov.io/gh/pandas-dev/pandas/pull/24719/diff?src=pr&el=tree#diff-cGFuZGFzL3V0aWwvdGVzdGluZy5weQ==) | `88.09% <0%> (+0.09%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24719?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24719?src=pr&el=footer). Last update [d46d2a5...f3232f1](https://codecov.io/gh/pandas-dev/pandas/pull/24719?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24719?src=pr&el=h1) Report
> Merging [#24719](https://codecov.io/gh/pandas-dev/pandas/pull/24719?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/d46d2a5ea900c59439dff58942e79ea8b39e918d?src=pr&el=desc) will **increase** coverage by `<.01%`.
> The diff coverage is `82.08%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/24719/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/24719?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #24719      +/-   ##
==========================================
+ Coverage   92.38%   92.38%   +<.01%     
==========================================
  Files         166      166              
  Lines       52321    52321              
==========================================
+ Hits        48337    48338       +1     
+ Misses       3984     3983       -1
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.8% <25.37%> (ø)` | :arrow_up: |
| #single | `43.06% <80.59%> (-0.01%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/24719?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/io/packers.py](https://codecov.io/gh/pandas-dev/pandas/pull/24719/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL3BhY2tlcnMucHk=) | `88.21% <0%> (ø)` | :arrow_up: |
| [pandas/io/sas/sas7bdat.py](https://codecov.io/gh/pandas-dev/pandas/pull/24719/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL3Nhcy9zYXM3YmRhdC5weQ==) | `91.16% <33.33%> (ø)` | :arrow_up: |
| [pandas/io/pytables.py](https://codecov.io/gh/pandas-dev/pandas/pull/24719/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL3B5dGFibGVzLnB5) | `92.31% <85.71%> (ø)` | :arrow_up: |
| [pandas/util/testing.py](https://codecov.io/gh/pandas-dev/pandas/pull/24719/diff?src=pr&el=tree#diff-cGFuZGFzL3V0aWwvdGVzdGluZy5weQ==) | `88.09% <0%> (+0.09%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24719?src=pr&el=continue).
> **Legend** - [Click here to learn more](https://docs.codecov.io/docs/codecov-delta)
> `Δ = absolute <relative> (impact)`, `ø = not affected`, `? = missing data`
> Powered by [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/24719?src=pr&el=footer). Last update [d46d2a5...f3232f1](https://codecov.io/gh/pandas-dev/pandas/pull/24719?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 thanks!