Retrieving last 20 file paths from directory

[dyerlee91]

Hello all,

I'm having a hard time getting this script across the finish line. I want to display only the last 20 file paths in the given directory, but I keep hitting a wall. Right now, it prints all the file paths in the folder, but I only want to the last 20. Can anyone help point me in the right direction?

import glob
import os
from pathlib import Path
path = (r'\\directory')
files = filter(lambda filepath: filepath.is_file(), Path(path).glob('*'))
for file in files:
   print(file.absolute())

Yoriz write Sep-24-2021, 01:09 PM:
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[snippsat]

Use code tags Code Tags.
Could do it like this.

import glob
import os
from pathlib import Path

path = (r'\\directory')
files = filter(lambda filepath: filepath.is_file(), Path(path).glob('*'))
file_lst = [f for f in files][-20:]
for file in file_lst:
    print(file)

[dyerlee91]

Awesome, thanks! Say I wanted to print the last 20 file paths from separate directories. For example, my setup would be:

(r'\\directory\asset1\asset1_runfile')
(r'\\directory\asset2\asset2_runfile')
(r'\\directory\asset3\asset3_runfile')
(r'\\directory\asset4\asset4_runfile')

How would I go about printing the last 20 file names of each "asset" without writing the same code with that slight variation over and over?

[DeaD_EyE]

I want to display only the last 20 file paths in the given directory, but I keep hitting a wall.

If you just use glob, the order is not alphabetical nor by modification time. Actually, I don't know if there is any kind of order. Maybe the inode-number define the order, but I am not certain.

You can use sorted with a key-function to define the order, and you can reverse it as well.
Her an example with sort_by_mtime, sort_by_ctime, sort_by_alpha:

from pathlib import Path


def sort_by_mtime(pathlike: Path):
    return pathlike.stat().st_mtime


def sort_by_ctime(pathlike: Path):
    return pathlike.stat().st_ctime


def sort_by_alpha(pathlike: Path):
    return str(pathlike.name)


def last_files(directory, pattern, last_files=10, key_function=None):
    
    path_iterator = Path(directory).glob(pattern)
    
    if callable(key_function):
        # if key_function is None or not callable, this branch is not executed
        sorted_iterator = sorted(path_iterator, key=key_function, reverse=True)
    else:
        # no key_function, so sorting by name alphanumeric implicit
        sorted_iterator = sorted(path_iterator, reverse=True)
    
    file_count = 0

    for path in sorted_iterator:
        if path.is_dir():
            # skipping directories
            continue
        
        if file_count >= last_files:
            return

        yield path
        
        file_count += 1

The function is a generator, you've to consume it.

files = list(last_files("/home/pi/Downloads", pattern="*.txt", last_files=5, key_function=sort_by_ctime))
# list files in Download
# with *.txt
# and the last 5 of it.
# the last file comes first in list, the second last file comes second ...

As you can see, you can also use functions as arguments. This function (sort_by_ctime) is called by sorted for each file to get a value back for comparison. This value could be an int or a str or something else, but must then always return the same data-type.

I hope this is not overcomplicated.