CLN: Remove ipython 2.x compat
Maybe closes https://github.com/pandas-dev/pandas/issues/25149
# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/25150?src=pr&el=h1) Report
> Merging [#25150](https://codecov.io/gh/pandas-dev/pandas/pull/25150?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/2e38d5552a5c7b2c0091cecddd483f4f08ad1d2c?src=pr&el=desc) will **increase** coverage by `0.03%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/25150/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/25150?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #25150      +/-   ##
==========================================
+ Coverage   92.37%    92.4%   +0.03%     
==========================================
  Files         166      166              
  Lines       52408    52382      -26     
==========================================
- Hits        48412    48405       -7     
+ Misses       3996     3977      -19
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.82% <ø> (+0.03%)` | :arrow_up: |
| #single | `42.87% <ø> (+0.01%)` | :arrow_up: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/25150?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/io/formats/console.py](https://codecov.io/gh/pandas-dev/pandas/pull/25150/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2Zvcm1hdHMvY29uc29sZS5weQ==) | `86.27% <ø> (+19.6%)` | :arrow_up: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/25150/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `96.97% <ø> (+0.15%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/25150?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/25150?src=pr&el=footer). Last update [2e38d55...d9c784d](https://codecov.io/gh/pandas-dev/pandas/pull/25150?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/25150?src=pr&el=h1) Report
> Merging [#25150](https://codecov.io/gh/pandas-dev/pandas/pull/25150?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/2e38d5552a5c7b2c0091cecddd483f4f08ad1d2c?src=pr&el=desc) will **increase** coverage by `0.03%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/25150/graphs/tree.svg?width=650&token=eZ4WkYLtcO&height=150&src=pr)](https://codecov.io/gh/pandas-dev/pandas/pull/25150?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #25150      +/-   ##
==========================================
+ Coverage   92.37%    92.4%   +0.03%     
==========================================
  Files         166      166              
  Lines       52408    52382      -26     
==========================================
- Hits        48412    48404       -8     
+ Misses       3996     3978      -18
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `90.82% <ø> (+0.03%)` | :arrow_up: |
| #single | `42.88% <ø> (+0.02%)` | :arrow_up: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/25150?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/io/formats/console.py](https://codecov.io/gh/pandas-dev/pandas/pull/25150/diff?src=pr&el=tree#diff-cGFuZGFzL2lvL2Zvcm1hdHMvY29uc29sZS5weQ==) | `86.27% <ø> (+19.6%)` | :arrow_up: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/25150/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `96.97% <ø> (+0.15%)` | :arrow_up: |
| [pandas/util/testing.py](https://codecov.io/gh/pandas-dev/pandas/pull/25150/diff?src=pr&el=tree#diff-cGFuZGFzL3V0aWwvdGVzdGluZy5weQ==) | `88.04% <0%> (-0.1%)` | :arrow_down: |
| [pandas/util/\_decorators.py](https://codecov.io/gh/pandas-dev/pandas/pull/25150/diff?src=pr&el=tree#diff-cGFuZGFzL3V0aWwvX2RlY29yYXRvcnMucHk=) | `91.5% <0%> (ø)` | :arrow_up: |
| [pandas/core/dtypes/dtypes.py](https://codecov.io/gh/pandas-dev/pandas/pull/25150/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZHR5cGVzL2R0eXBlcy5weQ==) | `95.6% <0%> (ø)` | :arrow_up: |
| [pandas/plotting/\_misc.py](https://codecov.io/gh/pandas-dev/pandas/pull/25150/diff?src=pr&el=tree#diff-cGFuZGFzL3Bsb3R0aW5nL19taXNjLnB5) | `38.68% <0%> (ø)` | :arrow_up: |
| [pandas/core/groupby/generic.py](https://codecov.io/gh/pandas-dev/pandas/pull/25150/diff?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZ3JvdXBieS9nZW5lcmljLnB5) | `87.15% <0%> (ø)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/25150?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/25150?src=pr&el=footer). Last update [2e38d55...9d7870f](https://codecov.io/gh/pandas-dev/pandas/pull/25150?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 lgtm. did you want a whatsnew for this? @TomAugspurger Agreed that this will fix the underlying issue. https://github.com/pandas-dev/pandas/pull/25237 can be reverted once this is merged. No whatsnew since it’s impossible to run ipython 3 with pandas 0.25