DOC: Improve truncate docstring (#17763)
- [ ] closes #17763


# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/17925?src=pr&el=h1) Report
> Merging [#17925](https://codecov.io/gh/pandas-dev/pandas/pull/17925?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/51c5f4d2a20179041114fac0262ef567d0b0373f?src=pr&el=desc) will **decrease** coverage by `0.01%`.
> The diff coverage is `n/a`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/17925/graphs/tree.svg?token=eZ4WkYLtcO&src=pr&width=650&height=150)](https://codecov.io/gh/pandas-dev/pandas/pull/17925?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #17925      +/-   ##
==========================================
- Coverage   91.23%   91.22%   -0.02%     
==========================================
  Files         163      163              
  Lines       50112    50113       +1     
==========================================
- Hits        45722    45714       -8     
- Misses       4390     4399       +9
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `89.03% <ø> (ø)` | :arrow_up: |
| #single | `40.31% <ø> (-0.07%)` | :arrow_down: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/17925?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/generic.py](https://codecov.io/gh/pandas-dev/pandas/pull/17925?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZ2VuZXJpYy5weQ==) | `92.53% <ø> (ø)` | :arrow_up: |
| [pandas/io/gbq.py](https://codecov.io/gh/pandas-dev/pandas/pull/17925?src=pr&el=tree#diff-cGFuZGFzL2lvL2dicS5weQ==) | `25% <0%> (-58.34%)` | :arrow_down: |
| [pandas/core/frame.py](https://codecov.io/gh/pandas-dev/pandas/pull/17925?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZnJhbWUucHk=) | `97.75% <0%> (-0.1%)` | :arrow_down: |
| [pandas/core/ops.py](https://codecov.io/gh/pandas-dev/pandas/pull/17925?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvb3BzLnB5) | `91.77% <0%> (+0.01%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/17925?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/17925?src=pr&el=footer). Last update [51c5f4d...c29db45](https://codecov.io/gh/pandas-dev/pandas/pull/17925?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 thanks @reidy-p 