How to get the latest file in a folder?

Question

Whatever is assigned to the files variable is incorrect. Use the following code.

import glob
import os

list_of_files = glob.glob('/path/to/folder/*') # * means all if need specific format then *.csv
latest_file = max(list_of_files, key=os.path.getctime)
print(latest_file)

max(files, key = os.path.getctime)

is quite incomplete code. What is files? It probably is a list of file names, coming out of os.listdir().

But this list lists only the filename parts (a. k. a. "basenames"), because their path is common. In order to use it correctly, you have to combine it with the path leading to it (and used to obtain it).

Such as (untested):

def newest(path):
    files = os.listdir(path)
    paths = [os.path.join(path, basename) for basename in files]
    return max(paths, key=os.path.getctime)

I lack the reputation to comment but ctime from Marlon Abeykoons response did not give the correct result for me. Using mtime does the trick though. (key=os.path.getmtime))

import glob
import os

list_of_files = glob.glob('/path/to/folder/*') # * means all if need specific format then *.csv
latest_file = max(list_of_files, key=os.path.getmtime)
print(latest_file)

I found two answers for that problem:

python os.path.getctime max does not return latest Difference between python - getmtime() and getctime() in unix system

I would suggest using glob.iglob() instead of the glob.glob(), as it is more efficient.

glob.iglob() Return an iterator which yields the same values as glob() without actually storing them all simultaneously.

Which means glob.iglob() will be more efficient.

I mostly use below code to find the latest file matching to my pattern:

LatestFile = max(glob.iglob(fileNamePattern),key=os.path.getctime)

---

NOTE: There are variants of max function, In case of finding the latest file we will be using below variant: max(iterable, *[, key, default])

which needs iterable so your first parameter should be iterable. In case of finding max of nums we can use beow variant : max (num1, num2, num3, *args[, key])

Try to sort items by creation time. Example below sorts files in a folder and gets first element which is latest.

import glob
import os

files_path = os.path.join(folder, '*')
files = sorted(
    glob.iglob(files_path), key=os.path.getctime, reverse=True) 
print files[0]

I've been using this in Python 3, including pattern matching on the filename.

from pathlib import Path

def latest_file(path: Path, pattern: str = "*"):
    files = path.glob(pattern)
    return max(files, key=lambda x: x.stat().st_ctime)

A much faster method on windows (0.05s), call a bat script that does this:

get_latest.bat

@echo off
for /f %%i in ('dir \\directory\in\question /b/a-d/od/t:c') do set LAST=%%i
%LAST%

where \\directory\in\question is the directory you want to investigate.

get_latest.py

from subprocess import Popen, PIPE
p = Popen("get_latest.bat", shell=True, stdout=PIPE,)
stdout, stderr = p.communicate()
print(stdout, stderr)

if it finds a file stdout is the path and stderr is None.

Use stdout.decode("utf-8").rstrip() to get the usable string representation of the file name.