Python - change given directory one level above or below [closed]

Question

is there a way to get one level above or below directory from the one that is given? For example '/a/b/c/' directory was entered in a function.

So function would return:

lvl_down = '/a/b/'
lvl_up = '/a/b/c/d/'

I think you can do it using 're' module (at least with one level below directory), but maybe there is more simple and better way to do it without regex?

Answer 1

I have no idea, how the function should know, that you want to go in directory d:

#!/usr/bin/python
import os.path

def lvl_down(path):
    return os.path.split(path)[0]

def lvl_up(path, up_dir):
    return os.path.join(path, up_dir)

print(lvl_down('a/b/c'))   # prints a/b
print(lvl_up('a/b/c','d')) # prints a/b/c/d

Note: Had another solution before, but os.path is a much better one.

Answer 2

Methods for manipulating paths can be found in the modules os and os.path.

os.path.join - Join one or more path components intelligently.

os.path.split - Split the pathname path into a pair, (head, tail) where tail is the last pathname component and head is everything leading up to that.

os.path.isdir - Return True if path is an existing directory.

os.listdir - Return a list containing the names of the entries in the directory given by path.

def parentDir(dir):
    return os.path.split(dir)[0]

def childDirs(dir):
    possibleChildren = [os.path.join(dir, file) for file in os.listdir(dir)]
    return [file for file in possibleChildren if os.path.isdir(file)]