`.path.parent` returns a string rather than a `Path`

[jfthuong]

The attribute .parent returns a string rather than a Path, like in pathlib.

from pathlib import Path

import pandas as pd
from pandas_path import path as _

df = pd.DataFrame({"file_path": [Path("tata.txt"), Path("toto/titi.txt")]})
df["parent"] = df.file_path.path.parent
df.to_dict()
#> { 'file_path': {0: WindowsPath('tata.txt'), 1: WindowsPath('toto/titi.txt')},
#>   'parent': {0: '.', 1: 'toto'}}

The current workaround is to apply a Path after getting the parent.

...
df["parent"] = df.file_path.path.parent.apply(Path)
df.to_dict()
#> { 'file_path': {0: WindowsPath('tata.txt'), 1: WindowsPath('toto/titi.txt')},
#>   'parent': {0: WindowsPath('.'), 1: WindowsPath('toto')}}

Let's note that the related test is currently expecting a string so this might be updated: https://github.com/drivendataorg/pandas-path/blob/8852e1c79113340127ba8c7c29f57c363128e3b2/pandas_path/tests.py#L56