[python] How to get only the last part of a path in Python?

In Python, suppose I have a path like this:

/folderA/folderB/folderC/folderD/

How can I get just the folderD part?

With python 3 you can use the pathlib module (pathlib.PurePath for example):

>>> import pathlib

>>> path = pathlib.PurePath('/folderA/folderB/folderC/folderD/')
>>> path.name
'folderD'

If you want the last folder name where a file is located:

>>> path = pathlib.PurePath('/folderA/folderB/folderC/folderD/file.py')
>>> path.parent.name
'folderD'

I like the parts method of Path for this:

grandparent_directory, parent_directory, filename = Path(export_filename).parts[-3:]
log.info(f'{t: <30}: {num_rows: >7} Rows exported to {grandparent_directory}/{parent_directory}/{filename}')

You could do

>>> import os
>>> os.path.basename('/folderA/folderB/folderC/folderD')

UPDATE1: This approach works in case you give it /folderA/folderB/folderC/folderD/xx.py. This gives xx.py as the basename. Which is not what you want I guess. So you could do this -

>>> import os
>>> path = "/folderA/folderB/folderC/folderD"
>>> if os.path.isdir(path):
        dirname = os.path.basename(path)

UPDATE2: As lars pointed out, making changes so as to accomodate trailing '/'.

>>> from os.path import normpath, basename
>>> basename(normpath('/folderA/folderB/folderC/folderD/'))
'folderD'

During my current projects, I'm often passing rear parts of a path to a function and therefore use the Path module. To get the n-th part in reverse order, I'm using:

from typing import Union
from pathlib import Path

def get_single_subpath_part(base_dir: Union[Path, str], n:int) -> str:
    if n ==0:
        return Path(base_dir).name
    for _ in range(n):
        base_dir = Path(base_dir).parent
    return getattr(base_dir, "name")

path= "/folderA/folderB/folderC/folderD/"

# for getting the last part:
print(get_single_subpath_part(path, 0))
# yields "folderD"

# for the second last
print(get_single_subpath_part(path, 1))
#yields "folderC"

Furthermore, to pass the n-th part in reverse order of a path containing the remaining path, I use:

from typing import Union
from pathlib import Path

def get_n_last_subparts_path(base_dir: Union[Path, str], n:int) -> Path:
    return Path(*Path(base_dir).parts[-n-1:])

path= "/folderA/folderB/folderC/folderD/"

# for getting the last part:
print(get_n_last_subparts_path(path, 0))
# yields a `Path` object of "folderD"

# for second last and last part together 
print(get_n_last_subparts_path(path, 1))
# yields a `Path` object of "folderc/folderD"

Note that this function returns a Pathobject which can easily be converted to a string (e.g. str(path))

I was searching for a solution to get the last foldername where the file is located, I just used split two times, to get the right part. It's not the question but google transfered me here.

pathname = "/folderA/folderB/folderC/folderD/filename.py"
head, tail = os.path.split(os.path.split(pathname)[0])
print(head + "   "  + tail)

Here is my approach:

>>> import os
>>> print os.path.basename(
        os.path.dirname('/folderA/folderB/folderC/folderD/test.py'))
folderD
>>> print os.path.basename(
        os.path.dirname('/folderA/folderB/folderC/folderD/'))
folderD
>>> print os.path.basename(
        os.path.dirname('/folderA/folderB/folderC/folderD'))
folderC

str = "/folderA/folderB/folderC/folderD/"
print str.split("/")[-2]

path = "/folderA/folderB/folderC/folderD/"
last = path.split('/').pop()