examples using os.walk()

[buran]

so, the problem is you incorrect expectation that os.walk() returns result in alphabetic/sorted order, which however is not the case

check
https://stackoverflow.com/a/18282401/4046632

Also, because paths has both dirs and files, it is normal to expect that when you sort it some [hidden] files/folders will come on the top, because of the . i.e. even if os.walk() returns folders in alphabetic order, when you sort mix of files and folders the result may differ.