Find file using Python

Question

I have a question, how to locate a file using python. The goal is to locate a file inside a directory and return all the way from the directory where the file is and if you do not find the file, return None. I created the code below, but it returns all the directories that do not contain the file and also the directory that contains the file. Can anyone check if it is correct or forgot something? Thanks!

import os

diret = "/"
filename = "teste"

def achar_arq():

for roots, dirs, files in os.walk(diret):

    if filename in files:
        print(os.path.join(roots,filename))
    if filename not in files:
        print('None')

print(achar_arq())

Answer 1

As of Python version 3.4 there are no more justifications¹ to use the library os to manipulate directories and files, since in this version the library was added pathlib, that abstracts the functions of os in a much simpler API to use.

To create an object that represents a directory just do:

diretorio = pathlib.Path('diretorio')

And to fetch all files with the name teste inside this directory just do:

arquivos = diretorio.glob('**/teste')

The ** indicates that the file may be at any subdirectory level, not just at the root.

For a directory structure similar to:

└ diretorio/
.   └ arquivos/
.   .   └ arquivos/
.   .   .   └ banana
.   .   .   └ teste
.   .   └ teste
.   └ teste

Just do:

diretorio = pathlib.Path('diretorio')
arquivos = diretorio.glob('**/teste')

for arquivo in arquivos:
    print(arquivo)

The exit would be:

arquivos/teste
arquivos/arquivos/teste
arquivos/arquivos/arquivos/teste

It is worth mentioning that the return of glob will be an eternal object of instances of pathlib.PosixPath, if you want to search how to manipulate such objects.

^{1) There is, but in the vast majority of cases the library pathlib can be used}