I need to get the latest file of a folder using python. While using the code:

我需要使用python获取文件夹的最新文件。在使用代码时：

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

I am getting the below error:

我收到以下错误：

FileNotFoundError: [WinError 2] The system cannot find the file specified: 'a'

FileNotFoundError：[WinError 2]系统找不到指定的文件：‘a’

优秀答案推荐

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

分配给FILES变量的任何内容都是不正确的。使用以下代码。

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().

这是一个非常不完整的代码。什么是文件？它可能是一个文件名列表，来自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).

但是这个列表只列出了文件名部分(也就是“基本名称”)，因为它们的路径是通用的。为了正确使用它，你必须将它与通向它的路径结合起来(并用来获得它)。

Such as (untested):

例如(未经测试)：

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))

我缺乏评论的声誉，但是马龙·阿贝昆斯的ctime回应并没有给我正确的结果。(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:

对于这个问题，我找到了两个答案：

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

在Unix系统中，Python os.path.getctime max不返回python-getmtime()和getctime()之间的最新差异

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

我在Python3中使用了这一点，包括对文件名进行模式匹配。

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

我建议使用lob.iglob()而不是lob.lobb()，因为这样效率更高。

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.

这意味着lob.iglob()将更加高效。

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

我主要使用以下代码来查找与我的模式匹配的最新文件：

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

LatestFile=max(lob.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])

注意：max函数有很多变体，为了找到最新的文件，我们将使用下面的变体：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])

它需要可迭代的，所以你的第一个参数应该是可迭代的。在寻找最大的nums的情况下，我们可以使用下面的变量：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.

尝试按创建时间对项目进行排序。下面的示例对文件夹中的文件进行排序，并获取最新的第一个元素。

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]

Most of the answers are correct but if there is a requirement like getting the latest two or three latest then it could fail or need to modify the code.

大多数答案都是正确的，但如果需要获得最新的两到三个，那么它可能会失败或需要修改代码。

I found the below sample is more useful and relevant as we can use the same code to get the latest 2,3 and n files too.

我发现下面的示例更有用，也更相关，因为我们也可以使用相同的代码来获取最新的2，3和n文件。

import glob
import os

folder_path = "/Users/sachin/Desktop/Files/"
files_path = os.path.join(folder_path, '*')
files = sorted(glob.iglob(files_path), key=os.path.getctime, reverse=True) 
print (files[0]) #latest file 
print (files[0],files[1]) #latest two files

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

Windows(0.05s)上的一种速度更快的方法是调用执行以下操作的BAT脚本：

get_latest.bat

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.

其中，\\DIRECTORY\IN\QUEST是您要调查的目录。

get_latest.py

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.

如果找到文件，则路径为stdout，而stderr为None。

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

使用stdout.decode(“utf-8”).rstrie()获取文件名的可用字符串表示。

(Edited to improve answer)

(编辑以改进答案)

First define a function get_latest_file

首先定义函数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 !

您也可以使用文档字符串！

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.

如果您使用的是Python3，则可以使用iglob。

Complete code to return the name of latest file:

完成代码以返回最新文件的名称：

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 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:

我尝试使用上面的建议，但我的程序崩溃了，然后我发现我试图识别的文件被使用了，当我试图使用‘os.path.getctime’时，它崩溃了。最终对我起作用的是：

    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

这个代码得到了两组文件列表之间的不常见对象，它不是最优雅的，如果同时创建多个文件，它可能会不稳定

On Linux you can also call shell tools from python

在Linux上，您还可以从Python调用外壳工具

subprocess.run requires python 3.5+

Subprocess.run需要使用python3.5+

import subprocess

def find_latest_files(target_dir, count):
    cmd = f"ls -t {target_dir} | head -n{count}"

    try:
        output = subprocess.run(cmd, shell=True, text=True, capture_output=True, check=False)
    except subprocess.CalledProcessError as err:
        sys.exit(f"Error: finding last modified file {err.output[1]}")

    # returns a list[]
    return output.stdout.splitlines()