Python function to lower case all sub-directories and files in a directory

lower_case_all.py

def lower_case_all(dirname):
    import os

    for dirpath, dirs, files in os.walk(dirname, topdown=False):

        for filename in files:
            os.rename(os.path.join(dirpath, filename),
                      os.path.join(dirpath, filename.lower()))

        for adir in dirs:
            os.rename(os.path.join(dirpath, adir),
                      os.path.join(dirpath, adir.lower()))

    os.rename(dirname, dirname.lower())
    
def lower_case_all_pathlib(dirname):
    '''
    Same but using pathlib
    '''
    import pathlib

    for path in dirname.rglob('*'):

        path.rename(path.parent / path.name.lower())