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#!/usr/bin/env python | |
""" | |
Fast duplicate file finder. | |
Usage: duplicates.py <folder> [<folder>...] | |
Based on https://stackoverflow.com/a/36113168/300783 | |
Modified for Python3 with some small code improvements. | |
""" | |
import os | |
import sys | |
import hashlib | |
from collections import defaultdict | |
def chunk_reader(fobj, chunk_size=1024): | |
""" Generator that reads a file in chunks of bytes """ | |
while True: | |
chunk = fobj.read(chunk_size) | |
if not chunk: | |
return | |
yield chunk | |
def get_hash(filename, first_chunk_only=False, hash_algo=hashlib.sha1): | |
hashobj = hash_algo() | |
with open(filename, "rb") as f: | |
if first_chunk_only: | |
hashobj.update(f.read(1024)) | |
else: | |
for chunk in chunk_reader(f): | |
hashobj.update(chunk) | |
return hashobj.digest() | |
def check_for_duplicates(paths): | |
files_by_size = defaultdict(list) | |
files_by_small_hash = defaultdict(list) | |
files_by_full_hash = dict() | |
for path in paths: | |
for dirpath, _, filenames in os.walk(path): | |
for filename in filenames: | |
full_path = os.path.join(dirpath, filename) | |
try: | |
# if the target is a symlink (soft one), this will | |
# dereference it - change the value to the actual target file | |
full_path = os.path.realpath(full_path) | |
file_size = os.path.getsize(full_path) | |
except OSError: | |
# not accessible (permissions, etc) - pass on | |
continue | |
files_by_size[file_size].append(full_path) | |
# For all files with the same file size, get their hash on the first 1024 bytes | |
for file_size, files in files_by_size.items(): | |
if len(files) < 2: | |
continue # this file size is unique, no need to spend cpu cycles on it | |
for filename in files: | |
try: | |
small_hash = get_hash(filename, first_chunk_only=True) | |
except OSError: | |
# the file access might've changed till the exec point got here | |
continue | |
files_by_small_hash[(file_size, small_hash)].append(filename) | |
# For all files with the hash on the first 1024 bytes, get their hash on the full | |
# file - collisions will be duplicates | |
for files in files_by_small_hash.values(): | |
if len(files) < 2: | |
# the hash of the first 1k bytes is unique -> skip this file | |
continue | |
for filename in files: | |
try: | |
full_hash = get_hash(filename, first_chunk_only=False) | |
except OSError: | |
# the file access might've changed till the exec point got here | |
continue | |
if full_hash in files_by_full_hash: | |
duplicate = files_by_full_hash[full_hash] | |
print("Duplicate found:\n - %s\n - %s\n" % (filename, duplicate)) | |
else: | |
files_by_full_hash[full_hash] = filename | |
if __name__ == "__main__": | |
if sys.argv[1:]: | |
check_for_duplicates(sys.argv[1:]) | |
else: | |
print("Usage: %s <folder> [<folder>...]" % sys.argv[0]) |
The original SO poster here 👋.
I would argue on this comment:
The script on stackoverflow has a bug which could lead to false positives.
It's not a bug, but sub-optimal execution - the small hashes are used for the input on the 2nd pass, not the final result; e.g. they don't pop up to the user, just increase the runtime.
Couple of comments on the gist:
- there are bugs, hidden in the exceptions handling - if an exception does occur, the value that was to be assigned in the caught block is used outside of it; after all, this was a hacky script for SO answer :)
- though not deprecated (and, probably never going to be), printf style formatting with
%s
is not the now-usual py3 way.
Thanks much for modifying this for Python3 and for posting it! Worked like a charm with no alterations needed.
I have found an issue with this script. I ran this script on my computer. One file was marked as a duplicate for many many other files.
The common file was: Default.rdp with a size of 0KB.
It was matched with several log files (text files) from a game I used to play (Star Wars: The Old Republic). These log files varied in size.
I copied and pasted just a few lines of output from the script:
Duplicate found:
\Documents\Backup from old laptop\Star Wars - The Old Republic\CombatLogs\combat_2014-07-29_21_58_20_214517.txt
\Documents\Default.rdp
Duplicate found:
\Documents\Backup from old laptop\Star Wars - The Old Republic\CombatLogs\combat_2014-08-02_13_37_30_520940.txt
\Documents\Default.rdp
Duplicate found:
\Documents\Backup from old laptop\Star Wars - The Old Republic\CombatLogs\combat_2014-08-10_00_13_50_659725.txt
\Documents\Default.rdp
Duplicate found:
\Documents\Backup from old laptop\Star Wars - The Old Republic\CombatLogs\combat_2014-08-13_12_09_11_572142.txt
\Documents\Default.rdp
What other information do you need to help with this?
I just looked further down the list and this same "Default.rdp" file also matched with several other files. It gets curiouser and curiouser.Very interesting! Are you sure the logfiles are not empty? Can you post them somewhere so I can try to reproduce this?
It's not a bug, but sub-optimal execution - the small hashes are used for the input on the 2nd pass, not the final result; e.g. they don't pop up to the user, just increase the runtime.
You're right 👍 I removed the comment.
I should have looked closer before I posted my previous comment. When I went back through and looked at the combat logs, the ones that were listed were in fact empty.
thank you for pointing that out to me. :)
You should add a condition to skip special files, such as named pipes. Otherwise, get_hash() will hang and the script will not terminate.
Hey guys, sorry if this is a really stupid question but I'm quite new to python!
Do I just drop it in the folder where i want to compare files?
Also, will this just report duplicates or actually remove duplicates? I want the latter, how can make that happen?
Any help is greatly appreciated:)
@ann1h1lan
You might want to check out organize where this code is used here
You can then define a rule like this to delete duplicates:
rules:
- folders:
- ~/Downloads
subfolders: true
filters:
- duplicate
actions:
- trash
Can this be modified to only show duplicate folders? What about duplicate folders whose parents aren't duplicates?
Can this be modified to only show duplicate folders? What about duplicate folders whose parents aren't duplicates?
Do you mean the snippet or the organize
config?
Of course it's possible. You'd have to recurse depth first into your folder tree and assign the hashes to compare.
Maybe this is a stupid question, but what would be the easiest way to only keep one of the duplicate files?
Hello,
First of all many thanks for this code.
I have used it and, it works, except for ".MOV" files.
Since I was interested in deleting duplicated files, I have added
if(Path(duplicate).exists()):
os.remove(duplicate)
print("Deleted duplicate found:\n - %s\n" % (duplicate))
right after
if full_hash in files_by_full_hash:
duplicate = files_by_full_hash[full_hash]
print("Duplicate found:\n - %s\n - %s\n" % (filename, duplicate))
As you see I use python pathlib.Path to test if file exists before deleting it because some times the algorithm identifies the same file as a duplicate of different other files, as it was for my case.
In my case I had 'path01/F1.jpg', 'path02/F1 (1).jpg', 'path02/G1.jpg' and 'path03/G (1).jpg' all with the same content.
The algorithm then pointed 'F1.jpg' as a duplicated file of 'F1 (1).jpg', 'G1.jpg' and 'G (1).jpg', pairing ('F1.jpg', 'F1 (1).jpg'), ('F1.jpg', 'G1.jpg') and ('F1.jpg','G (1).jpg').
After deleting 'F1.jpg' for the first pair, it skips the other deletes since the same 'F1.jpg' file is pointed as duplicated.
Because of that, the algorithm does remove duplicated file, however, since it detects duplication in pairs, I had to run it several times, until I've got no duplicated files to delete.
I shared my experience just in case you would like to improve your code.
All the best to you.
Regards,
Roberto
For me, deleting the file instead of the duplicate solved the problem
so instead of
if(Path(duplicate).exists()):
os.remove(duplicate)
print("Deleted duplicate found:\n - %s\n" % (duplicate))
I did
if(Path(filename).exists()):
os.remove(filename)
print("Deleted duplicate found:\n - %s\n" % (filename))
Great file! I wanted to group all duplicates together, not just pairs of them. I also wanted just one printout of all duplicates at the end of the script. If anyone else wants this, I created a fork.
E.g. if you have 4 files that are all duplicates of each other, it would print
Duplicate found:
- <path>\check_dups\myfile - Copy (2).rtf
- <path>\check_dups\myfile - Copy (3).rtf
- <path>\check_dups\myfile - Copy.rtf
- <path>\check_dups\myfile.rtf
In contrast, the original script would print:
Duplicate found:
- <path>\check_dups\myfile - Copy (3).rtf
- <path>\check_dups\myfile - Copy (2).rtf
Duplicate found:
- <path>\check_dups\myfile - Copy.rtf
- <path>\check_dups\myfile - Copy (2).rtf
Duplicate found:
- <path>\check_dups\myfile.rtf
- <path>\check_dups\myfile - Copy (2).rtf
For our use, I quickly added a "-d" argument, for optional deletion.
The diff lines are:
- 13
from pathlib import Path
- 35
def check_for_duplicates(paths, b_delete=False):
- 81
if full_hash in files_by_full_hash:
duplicate = files_by_full_hash[full_hash]
print("Duplicate found:\n - %s\n - %s" % (filename, duplicate))
if(b_delete and Path(filename).exists()):
os.remove(filename)
print(" 1st file removed:\n - %s\n" % (filename))
- 88
if __name__ == "__main__":
if len(sys.argv)<=1:
print("Usage: %s [-d] <folder> [<folder>...]" % sys.argv[0])
elif sys.argv[1]=='-d':
if sys.argv[2:]:
check_for_duplicates(sys.argv[2:], b_delete=True)
elif sys.argv[1:]:
check_for_duplicates(sys.argv[1:])
hiii guys i am new to python so i want to know where will i drop the folder path to detect the duplicates
need some help it would be much appreciated
You run this file with python3 duplicates.py folder1 path/to/folder2 folder3
and so on.
can you explain more how to do it ?
Install python 3, save this gist as duplicates.py
and run the given command in a terminal of your choice.
thanks @tfeldmann!
In case anyone else stumbles here - in my fork I have enabled automated hardlinking of duplicates. This is not something you want to do lightly as it can mess up your system, but it is what I was looking for to help reduce the size of my backups using rsnapshot (which does not handle moving files very well).
For you Thomas maybe a small improvement to the 'base' gist is grouping all files together using the true_duplicates
dict, rather than just printing them out one by one.
Hello, I understand your code and it is very well and you did the great work, but I have little bit problem with it like,
path = askdirectory(title='Select a directory')
if I want to ask from user to select path folder as I mentioned the script so, for this kind of solution where and how can I use that script.
@abidkhan03 You can use something like Gooey to create a simple GUI for this script
thanks @tfeldmann!
In case anyone else stumbles here - in my fork I have enabled automated hardlinking of duplicates. This is not something you want to do lightly as it can mess up your system, but it is what I was looking for to help reduce the size of my backups using rsnapshot (which does not handle moving files very well).
@jcjveraa random question about the functionality of what you describe as "hardlinking" a duplicate.
I've read through the code and somewhere between line 120 to 146 of well written code I'm having trouble keeping it all in my head. You had me until you started mixing a hash
with an inode
or file_node
it goes fuzzy for me. (non CS major) =)
Can you tell me more?
- Are we making indexes that reference hard file paths?
- Are we making indexes of indexes for speeding up future searches
- Are we creating a 'never move or delete hash' that breaks if modified?
Hi there @datatalking - maybe the confusion starts at what hard links are?
To avoid wrong impressions by the way - the code I added wouldn't be acceptable by my standards if it wasn't a gist (ie a proof of concept / handy tool), not "well written" on my part ;-) my professional code is a lot more readable.
To your question:
A harddisk/ssd in and of itself doesn't contain files, but raw data (bytes). The "filesystem", like ext4 or ntfs or fat32, that we put on top of this disk, helps to assign meaning to sets of bytes saying "a certain file exists, and this file is stored at this and this 'block (of bytes)'". If you search online you'll find that these inode-things have role to play there. Think of this as the "path" of a file, or a hard "link" to the file, like www.github.com is a link to this site.
In case we find there are two files that exist, ie we have two separate hard links (which is the same - a file "exists" because there is at least one hard link to it, else it is simply unreachable data on a hard disk), but we find out by computing the hash of the file that these two files are effectively identical (e.g. you just copied a file using copy-paste in your windows system), my addition will "unlink" (delete) one of the files and replace it with a hard link.
Now the copied file and the original both refer to the same set of bytes on the disk, rather than a real copy of the bytes. This means there is less disk space used. It also means that changing the original also changes the 'copy', as it is no longer a true copy but a reference to the same bytes on disk as the original. That can be not at all what you want, hence this is a little dangerous.
In my usecase though this is exactly what I need as it helps a lot in keeping the size of "read only" backups down. It is easy to "undo" the hard linking when restoring the backup if that is required.
Note: a hard link differs from a "soft link" (or symlink / windows shortcut) in that as long as either of the "files" (= at least one hard link) exists, the data will remain on the disk.
The data is "deleted" when the last hard link to it is 'unlinked'. That fact is desired in my use case - soft links could mean I lose data in the backups if I would delete some file, as in that case deleting the original (unlinking the hard link) results in a broken shortcut and the data would be gone. With multiple hardlinks such as my version of the script creates, the data will be preserved until it is truly no longer required. Google can tell you more on this :-)
Note, when I say that hardlinking can be undone this is "... by an expert user and then still only to a certain extent". Noting comes for free, and what you will lose/need to restore via other means (if required) is file metadata including file access permissions. If like in my case this is not an issue, then my method works, but your mileage may vary :-)
I recently had a task I thought was IO bound : I had to read 400 K files, but when I multi-threaded it on 8 threads, the performance definitely improved, by a factor I would guess at least of 2 or 3. As here there may be millions of files, I think it could be worthwhile to test.