BUG Fix for Issue #12565 - font size on secondary_y
There may be other plotting methods that need testing.

 - [ ] closes #12565
 - [ ] tests added / passed
 - [ ] passes ``git diff upstream/master -u -- "*.py" | flake8 --diff``
 - [ ] whatsnew entry

Hello @Morgan243! Thanks for updating the PR.



 - In the file [`pandas/tests/plotting/test_frame.py`](https://github.com/pandas-dev/pandas/blob/4642a2d2c5f3e84765c3c7dd3aec57f771ac9ba8/pandas/tests/plotting/test_frame.py), following are the PEP8 issues :

> [Line 294:9](https://github.com/pandas-dev/pandas/blob/4642a2d2c5f3e84765c3c7dd3aec57f771ac9ba8/pandas/tests/plotting/test_frame.py#L294): [E741](https://duckduckgo.com/?q=pep8%20E741) ambiguous variable name 'l'
> [Line 302:9](https://github.com/pandas-dev/pandas/blob/4642a2d2c5f3e84765c3c7dd3aec57f771ac9ba8/pandas/tests/plotting/test_frame.py#L302): [E741](https://duckduckgo.com/?q=pep8%20E741) ambiguous variable name 'l'



##### Comment last updated on July 15, 2017 at 20:25 Hours UTC # [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/16952?src=pr&el=h1) Report
> Merging [#16952](https://codecov.io/gh/pandas-dev/pandas/pull/16952?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/7500218947bffd4915832e9037d9f48991e53ca3?src=pr&el=desc) will **decrease** coverage by `0.01%`.
> The diff coverage is `100%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/16952/graphs/tree.svg?src=pr&token=eZ4WkYLtcO&width=650&height=150)](https://codecov.io/gh/pandas-dev/pandas/pull/16952?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #16952      +/-   ##
==========================================
- Coverage   90.98%   90.97%   -0.02%     
==========================================
  Files         161      161              
  Lines       49288    49292       +4     
==========================================
- Hits        44846    44844       -2     
- Misses       4442     4448       +6
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `88.74% <100%> (ø)` | :arrow_up: |
| #single | `40.19% <0%> (-0.07%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/16952?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/plotting/\_core.py](https://codecov.io/gh/pandas-dev/pandas/pull/16952?src=pr&el=tree#diff-cGFuZGFzL3Bsb3R0aW5nL19jb3JlLnB5) | `82.72% <100%> (+0.2%)` | :arrow_up: |
| [pandas/io/gbq.py](https://codecov.io/gh/pandas-dev/pandas/pull/16952?src=pr&el=tree#diff-cGFuZGFzL2lvL2dicS5weQ==) | `25% <0%> (-58.34%)` | :arrow_down: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/16952?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `97.76% <0%> (-0.1%)` | :arrow_down: |
| [pandas/plotting/\_timeseries.py](https://codecov.io/gh/pandas-dev/pandas/pull/16952?src=pr&el=tree#diff-cGFuZGFzL3Bsb3R0aW5nL190aW1lc2VyaWVzLnB5) | `60.73% <0%> (+0.52%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/16952?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/16952?src=pr&el=footer). Last update [7500218...9e06e9b](https://codecov.io/gh/pandas-dev/pandas/pull/16952?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/16952?src=pr&el=h1) Report
> Merging [#16952](https://codecov.io/gh/pandas-dev/pandas/pull/16952?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/7500218947bffd4915832e9037d9f48991e53ca3?src=pr&el=desc) will **decrease** coverage by `0.01%`.
> The diff coverage is `100%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/16952/graphs/tree.svg?width=650&height=150&src=pr&token=eZ4WkYLtcO)](https://codecov.io/gh/pandas-dev/pandas/pull/16952?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #16952      +/-   ##
==========================================
- Coverage   90.98%   90.97%   -0.02%     
==========================================
  Files         161      161              
  Lines       49288    49292       +4     
==========================================
- Hits        44846    44844       -2     
- Misses       4442     4448       +6
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `88.74% <100%> (ø)` | :arrow_up: |
| #single | `40.19% <0%> (-0.07%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/16952?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/plotting/\_core.py](https://codecov.io/gh/pandas-dev/pandas/pull/16952?src=pr&el=tree#diff-cGFuZGFzL3Bsb3R0aW5nL19jb3JlLnB5) | `82.72% <100%> (+0.2%)` | :arrow_up: |
| [pandas/io/gbq.py](https://codecov.io/gh/pandas-dev/pandas/pull/16952?src=pr&el=tree#diff-cGFuZGFzL2lvL2dicS5weQ==) | `25% <0%> (-58.34%)` | :arrow_down: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/16952?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `97.76% <0%> (-0.1%)` | :arrow_down: |
| [pandas/core/series.py](https://codecov.io/gh/pandas-dev/pandas/pull/16952?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvc2VyaWVzLnB5) | `94.89% <0%> (-0.01%)` | :arrow_down: |
| [pandas/core/dtypes/missing.py](https://codecov.io/gh/pandas-dev/pandas/pull/16952?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZHR5cGVzL21pc3NpbmcucHk=) | `87.03% <0%> (+0.16%)` | :arrow_up: |
| [pandas/plotting/\_timeseries.py](https://codecov.io/gh/pandas-dev/pandas/pull/16952?src=pr&el=tree#diff-cGFuZGFzL3Bsb3R0aW5nL190aW1lc2VyaWVzLnB5) | `60.73% <0%> (+0.52%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/16952?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/16952?src=pr&el=footer). Last update [7500218...4642a2d](https://codecov.io/gh/pandas-dev/pandas/pull/16952?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 @Morgan243 : Ping when tests pass, and we will merge this! @gfyoung tests passed! Thanks @Morgan243 !