Fix some lgtm alerts
Hi,
I just wanted to quickly fix a few alerts flagged up by lgtm.com. These are mostly simple ones but they were a few misnamed arguments in some calls. 

A total of 209 alerts have been found by lgtm.com, you can enable PR integration for automated PR reviews and flag these in the future before they find their way to the code base.
https://lgtm.com/projects/g/pydata/pandas/

I'm a big fan of pandas, I hope you'll find these useful!

 - [ ] closes #xxxx
 - [ ] tests added / passed
 - [x] passes ``git diff upstream/master --name-only -- '*.py' | flake8 --diff``
 - [ ] whatsnew entry
# [Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/16613?src=pr&el=h1) Report
> Merging [#16613](https://codecov.io/gh/pandas-dev/pandas/pull/16613?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/697d0269aa6903be75db97afb45f9976abd2406d?src=pr&el=desc) will **increase** coverage by `<.01%`.
> The diff coverage is `66.66%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/16613/graphs/tree.svg?src=pr&token=eZ4WkYLtcO&width=650&height=150)](https://codecov.io/gh/pandas-dev/pandas/pull/16613?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #16613      +/-   ##
==========================================
+ Coverage   90.93%   90.93%   +<.01%     
==========================================
  Files         161      161              
  Lines       49267    49263       -4     
==========================================
- Hits        44800    44798       -2     
+ Misses       4467     4465       -2
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `88.69% <66.66%> (ø)` | :arrow_up: |
| #single | `40.22% <0%> (ø)` | :arrow_up: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/16613?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/tseries/offsets.py](https://codecov.io/gh/pandas-dev/pandas/pull/16613?src=pr&el=tree#diff-cGFuZGFzL3RzZXJpZXMvb2Zmc2V0cy5weQ==) | `97.12% <ø> (-0.01%)` | :arrow_down: |
| [pandas/core/internals.py](https://codecov.io/gh/pandas-dev/pandas/pull/16613?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW50ZXJuYWxzLnB5) | `93.43% <ø> (+0.03%)` | :arrow_up: |
| [pandas/io/parsers.py](https://codecov.io/gh/pandas-dev/pandas/pull/16613?src=pr&el=tree#diff-cGFuZGFzL2lvL3BhcnNlcnMucHk=) | `95.43% <0%> (ø)` | :arrow_up: |
| [pandas/core/dtypes/cast.py](https://codecov.io/gh/pandas-dev/pandas/pull/16613?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZHR5cGVzL2Nhc3QucHk=) | `86.89% <0%> (ø)` | :arrow_up: |
| [pandas/core/sparse/array.py](https://codecov.io/gh/pandas-dev/pandas/pull/16613?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvc3BhcnNlL2FycmF5LnB5) | `91.46% <100%> (ø)` | :arrow_up: |
| [pandas/core/indexes/interval.py](https://codecov.io/gh/pandas-dev/pandas/pull/16613?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9pbnRlcnZhbC5weQ==) | `92.58% <100%> (ø)` | :arrow_up: |
| [pandas/core/generic.py](https://codecov.io/gh/pandas-dev/pandas/pull/16613?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZ2VuZXJpYy5weQ==) | `92.36% <100%> (+0.04%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/16613?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/16613?src=pr&el=footer). Last update [697d026...eecbbb8](https://codecov.io/gh/pandas-dev/pandas/pull/16613?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/16613?src=pr&el=h1) Report
> Merging [#16613](https://codecov.io/gh/pandas-dev/pandas/pull/16613?src=pr&el=desc) into [master](https://codecov.io/gh/pandas-dev/pandas/commit/697d0269aa6903be75db97afb45f9976abd2406d?src=pr&el=desc) will **increase** coverage by `<.01%`.
> The diff coverage is `66.66%`.

[![Impacted file tree graph](https://codecov.io/gh/pandas-dev/pandas/pull/16613/graphs/tree.svg?height=150&width=650&src=pr&token=eZ4WkYLtcO)](https://codecov.io/gh/pandas-dev/pandas/pull/16613?src=pr&el=tree)

```diff
@@            Coverage Diff             @@
##           master   #16613      +/-   ##
==========================================
+ Coverage   90.93%   90.93%   +<.01%     
==========================================
  Files         161      161              
  Lines       49267    49263       -4     
==========================================
- Hits        44800    44798       -2     
+ Misses       4467     4465       -2
```

| Flag | Coverage Δ | |
|---|---|---|
| #multiple | `88.69% <66.66%> (ø)` | :arrow_up: |
| #single | `40.22% <0%> (ø)` | :arrow_up: |

| [Impacted Files](https://codecov.io/gh/pandas-dev/pandas/pull/16613?src=pr&el=tree) | Coverage Δ | |
|---|---|---|
| [pandas/core/internals.py](https://codecov.io/gh/pandas-dev/pandas/pull/16613?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW50ZXJuYWxzLnB5) | `93.43% <ø> (+0.03%)` | :arrow_up: |
| [pandas/tseries/offsets.py](https://codecov.io/gh/pandas-dev/pandas/pull/16613?src=pr&el=tree#diff-cGFuZGFzL3RzZXJpZXMvb2Zmc2V0cy5weQ==) | `97.12% <ø> (-0.01%)` | :arrow_down: |
| [pandas/core/dtypes/cast.py](https://codecov.io/gh/pandas-dev/pandas/pull/16613?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZHR5cGVzL2Nhc3QucHk=) | `86.89% <0%> (ø)` | :arrow_up: |
| [pandas/io/parsers.py](https://codecov.io/gh/pandas-dev/pandas/pull/16613?src=pr&el=tree#diff-cGFuZGFzL2lvL3BhcnNlcnMucHk=) | `95.43% <0%> (ø)` | :arrow_up: |
| [pandas/core/sparse/array.py](https://codecov.io/gh/pandas-dev/pandas/pull/16613?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvc3BhcnNlL2FycmF5LnB5) | `91.46% <100%> (ø)` | :arrow_up: |
| [pandas/core/indexes/interval.py](https://codecov.io/gh/pandas-dev/pandas/pull/16613?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvaW5kZXhlcy9pbnRlcnZhbC5weQ==) | `92.58% <100%> (ø)` | :arrow_up: |
| [pandas/core/generic.py](https://codecov.io/gh/pandas-dev/pandas/pull/16613?src=pr&el=tree#diff-cGFuZGFzL2NvcmUvZ2VuZXJpYy5weQ==) | `92.36% <100%> (+0.04%)` | :arrow_up: |

------

[Continue to review full report at Codecov](https://codecov.io/gh/pandas-dev/pandas/pull/16613?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/16613?src=pr&el=footer). Last update [697d026...eecbbb8](https://codecov.io/gh/pandas-dev/pandas/pull/16613?src=pr&el=lastupdated). Read the [comment docs](https://docs.codecov.io/docs/pull-request-comments).
 thanks these look like good catches. This is all deprecated / not heavily tested code so makes sense that the style checker found this.

 so is there something we can hook up thru github to check this?  @jreback absolutely, you can activate it at https://lgtm.com/projects/g/pydata/pandas/ci/ once you've logged in with your GitHub account
see https://lgtm.com/docs/lgtm/config/pr-integration for details
