I need to get the latest file of a folder using python. While using the code:
max(files, key = os.path.getctime)
I am getting the below error:
FileNotFoundError: [WinError 2] The system cannot find the file specified: 'a'
This question is related to
python
python-3.x
python-2.7
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)
I have tried to use the above suggestions and my program crashed, than I figured out the file I'm trying to identify was used and when trying to use 'os.path.getctime' it crashed. what finally worked for me was:
files_before = glob.glob(os.path.join(my_path,'*'))
**code where new file is created**
new_file = set(files_before).symmetric_difference(set(glob.glob(os.path.join(my_path,'*'))))
this codes gets the uncommon object between the two sets of file lists its not the most elegant, and if multiple files are created at the same time it would probably won't be stable
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)
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]
(Edited to improve answer)
First define a function get_latest_file
def get_latest_file(path, *paths):
fullpath = os.path.join(path, paths)
...
get_latest_file('example', 'files','randomtext011.*.txt')
You may also use a docstring !
def get_latest_file(path, *paths):
"""Returns the name of the latest (most recent) file
of the joined path(s)"""
fullpath = os.path.join(path, *paths)
If you use Python 3, you can use iglob instead.
Complete code to return the name of latest file:
def get_latest_file(path, *paths):
"""Returns the name of the latest (most recent) file
of the joined path(s)"""
fullpath = os.path.join(path, *paths)
files = glob.glob(fullpath) # You may use iglob in Python3
if not files: # I prefer using the negation
return None # because it behaves like a shortcut
latest_file = max(files, key=os.path.getctime)
_, filename = os.path.split(latest_file)
return filename
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])
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.
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
Source: Stackoverflow.com