我正在编写一个 Python 程序来查找和删除文件夹中的重复文件。
我有多个 mp3 文件和一些其他文件的副本。我正在使用 sh1 算法。
如何找到这些重复文件并将其删除？
【问题讨论】：
标签： python file duplicates
其他解决方案中的方法非常酷，但它们忘记了重复文件的一个重要属性——它们具有相同的文件大小。仅对相同大小的文件计算昂贵的哈希将节省大量 CPU；最后的性能比较，这里是解释。
迭代@nosklo 给出的可靠答案，并借用@Raffi 的想法来获得每个文件开头的快速散列，并仅在快速散列中的冲突计算完整的散列，以下是步骤：
代码：
#!/usr/bin/env python
# if running in py3, change the shebang, drop the next import for readability (it does no harm in py3)
from __future__ import print_function # py2 compatibility
from collections import defaultdict
import hashlib
import os
import sys
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=hashlib.sha1):
hashobj = hash()
file_object = open(filename, 'rb')
if first_chunk_only:
hashobj.update(file_object.read(1024))
else:
for chunk in chunk_reader(file_object):
hashobj.update(chunk)
hashed = hashobj.digest()
file_object.close()
return hashed
def check_for_duplicates(paths, hash=hashlib.sha1):
hashes_by_size = defaultdict(list) # dict of size_in_bytes: [full_path_to_file1, full_path_to_file2, ]
hashes_on_1k = defaultdict(list) # dict of (hash1k, size_in_bytes): [full_path_to_file1, full_path_to_file2, ]
hashes_full = {} # dict of full_file_hash: full_path_to_file_string
for path in paths:
for dirpath, dirnames, filenames in os.walk(path):
# get all files that have the same size - they are the collision candidates
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)
hashes_by_size[file_size].append(full_path)
except (OSError,):
# not accessible (permissions, etc) - pass on
continue
# For all files with the same file size, get their hash on the 1st 1024 bytes only
for size_in_bytes, files in hashes_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)
# the key is the hash on the first 1024 bytes plus the size - to
# avoid collisions on equal hashes in the first part of the file
# credits to @Futal for the optimization
hashes_on_1k[(small_hash, size_in_bytes)].append(filename)
except (OSError,):
# the file access might've changed till the exec point got here
continue
# For all files with the hash on the 1st 1024 bytes, get their hash on the full file - collisions will be duplicates
for __, files_list in hashes_on_1k.items():
if len(files_list) < 2:
continue # this hash of fist 1k file bytes is unique, no need to spend cpy cycles on it
for filename in files_list:
try:
full_hash = get_hash(filename, first_chunk_only=False)
duplicate = hashes_full.get(full_hash)
if duplicate:
print("Duplicate found: {} and {}".format(filename, duplicate))
else:
hashes_full[full_hash] = filename
except (OSError,):
# the file access might've changed till the exec point got here
continue
if __name__ == "__main__":
if sys.argv[1:]:
check_for_duplicates(sys.argv[1:])
else:
print("Please pass the paths to check as parameters to the script")
还有，这是有趣的部分 - 性能比较。
基线 -
处理器：Feroceon 88FR131 rev 1 (v5l) BogoMIPS : 1599.07
（即我的低端 NAS :)，运行 Python 2.7.11。
所以，@nosklo 非常方便的解决方案的输出：
root@NAS:InstantUpload# time ~/scripts/checkDuplicates.py
Duplicate found: ./IMG_20151231_143053 (2).jpg and ./IMG_20151231_143053.jpg
Duplicate found: ./IMG_20151125_233019 (2).jpg and ./IMG_20151125_233019.jpg
Duplicate found: ./IMG_20160204_150311.jpg and ./IMG_20160204_150311 (2).jpg
Duplicate found: ./IMG_20160216_074620 (2).jpg and ./IMG_20160216_074620.jpg
real 5m44.198s
user 4m44.550s
sys 0m33.530s
而且，这里是大小检查过滤器的版本，然后是小散列，如果发现冲突，最后是完整散列：
root@NAS:InstantUpload# time ~/scripts/checkDuplicatesSmallHash.py . "/i-data/51608399/photo/Todor phone"
Duplicate found: ./IMG_20160216_074620 (2).jpg and ./IMG_20160216_074620.jpg
Duplicate found: ./IMG_20160204_150311.jpg and ./IMG_20160204_150311 (2).jpg
Duplicate found: ./IMG_20151231_143053 (2).jpg and ./IMG_20151231_143053.jpg
Duplicate found: ./IMG_20151125_233019 (2).jpg and ./IMG_20151125_233019.jpg
real 0m1.398s
user 0m1.200s
sys 0m0.080s
两个版本各运行 3 次，以获得所需时间的平均值。
所以v1是(user+sys)284s，另一个-2s；相当不同，呵呵:) 随着这一增加，人们可以使用 SHA512，甚至更高级 - 性能损失会因所需的计算量减少而减轻。
否定：
【讨论】：
hashes_on_1k 和 hashes_full 会比较可能具有不同大小的文件的哈希值。您应该使用元组（大小，散列）作为键，而不是单独使用散列。如果有数百万个文件，风险不容忽视。
os.remove(duplicate)，风险自负。 @prismspecs
此版本使用文件大小和内容的哈希值来查找重复项。 您可以传递多个路径，它会递归扫描所有路径并报告找到的所有重复项。
import sys
import os
import hashlib
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 check_for_duplicates(paths, hash=hashlib.sha1):
hashes = {}
for path in paths:
for dirpath, dirnames, filenames in os.walk(path):
for filename in filenames:
full_path = os.path.join(dirpath, filename)
hashobj = hash()
for chunk in chunk_reader(open(full_path, 'rb')):
hashobj.update(chunk)
file_id = (hashobj.digest(), os.path.getsize(full_path))
duplicate = hashes.get(file_id, None)
if duplicate:
print "Duplicate found: %s and %s" % (full_path, duplicate)
else:
hashes[file_id] = full_path
if sys.argv[1:]:
check_for_duplicates(sys.argv[1:])
else:
print "Please pass the paths to check as parameters to the script"
【讨论】：
python myscript.py c:\path1 c:\path2
try: for chunk..... except OSError: print('Skipping file')
def remove_duplicates(dir):
unique = []
for filename in os.listdir(dir):
if os.path.isfile(filename):
filehash = md5.md5(file(filename).read()).hexdigest()
if filehash not in unique:
unique.append(filehash)
else:
os.remove(filename)
//编辑：
对于 MP3 你可能也对这个话题感兴趣Detect duplicate MP3 files with different bitrates and/or different ID3 tags?
【讨论】：
hashlib.md5(open(filename, 'rb').read()).hexdigest() 时，它起作用了正确。
前段时间我用 Python 写过一个——欢迎你使用它。
import sys
import os
import hashlib
check_path = (lambda filepath, hashes, p = sys.stdout.write:
(lambda hash = hashlib.sha1 (file (filepath).read ()).hexdigest ():
((hash in hashes) and (p ('DUPLICATE FILE\n'
' %s\n'
'of %s\n' % (filepath, hashes[hash])))
or hashes.setdefault (hash, filepath)))())
scan = (lambda dirpath, hashes = {}:
map (lambda (root, dirs, files):
map (lambda filename: check_path (os.path.join (root, filename), hashes), files), os.walk (dirpath)))
((len (sys.argv) > 1) and scan (sys.argv[1]))
【讨论】：
如果要分析许多“大尺寸”文件（图像、mp3、pdf 文档），使用以下比较算法会很有趣/更快：
对文件的前 N 个字节（比如 1KB）执行第一次快速哈希。这个哈希会说文件是否不同，但不会说两个文件是否完全相同（哈希的准确性，从磁盘读取的数据有限）
第二个较慢的散列，如果在第一阶段发生冲突，则更准确并在文件的整个内容上执行
这是该算法的一个实现：
import hashlib
def Checksum(current_file_name, check_type = 'sha512', first_block = False):
"""Computes the hash for the given file. If first_block is True,
only the first block of size size_block is hashed."""
size_block = 1024 * 1024 # The first N bytes (1KB)
d = {'sha1' : hashlib.sha1, 'md5': hashlib.md5, 'sha512': hashlib.sha512}
if(not d.has_key(check_type)):
raise Exception("Unknown checksum method")
file_size = os.stat(current_file_name)[stat.ST_SIZE]
with file(current_file_name, 'rb') as f:
key = d[check_type].__call__()
while True:
s = f.read(size_block)
key.update(s)
file_size -= size_block
if(len(s) < size_block or first_block):
break
return key.hexdigest().upper()
def find_duplicates(files):
"""Find duplicates among a set of files.
The implementation uses two types of hashes:
- A small and fast one one the first block of the file (first 1KB),
- and in case of collision a complete hash on the file. The complete hash
is not computed twice.
It flushes the files that seems to have the same content
(according to the hash method) at the end.
"""
print 'Analyzing', len(files), 'files'
# this dictionary will receive small hashes
d = {}
# this dictionary will receive full hashes. It is filled
# only in case of collision on the small hash (contains at least two
# elements)
duplicates = {}
for f in files:
# small hash to be fast
check = Checksum(f, first_block = True, check_type = 'sha1')
if(not d.has_key(check)):
# d[check] is a list of files that have the same small hash
d[check] = [(f, None)]
else:
l = d[check]
l.append((f, None))
for index, (ff, checkfull) in enumerate(l):
if(checkfull is None):
# computes the full hash in case of collision
checkfull = Checksum(ff, first_block = False)
l[index] = (ff, checkfull)
# for each new full hash computed, check if their is
# a collision in the duplicate dictionary.
if(not duplicates.has_key(checkfull)):
duplicates[checkfull] = [ff]
else:
duplicates[checkfull].append(ff)
# prints the detected duplicates
if(len(duplicates) != 0):
print
print "The following files have the same sha512 hash"
for h, lf in duplicates.items():
if(len(lf)==1):
continue
print 'Hash value', h
for f in lf:
print '\t', f.encode('unicode_escape') if \
type(f) is types.UnicodeType else f
return duplicates
find_duplicates 函数获取文件列表。这样，也可以比较两个目录（例如，为了更好地同步它们的内容。）创建具有指定扩展名的文件列表并避免进入某些目录的函数示例如下：
def getFiles(_path, extensions = ['.png'],
subdirs = False, avoid_directories = None):
"""Returns the list of files in the path :'_path',
of extension in 'extensions'. 'subdir' indicates if
the search should also be performed in the subdirectories.
If extensions = [] or None, all files are returned.
avoid_directories: if set, do not parse subdirectories that
match any element of avoid_directories."""
l = []
extensions = [p.lower() for p in extensions] if not extensions is None \
else None
for root, dirs, files in os.walk(_path, topdown=True):
for name in files:
if(extensions is None or len(extensions) == 0 or \
os.path.splitext(name)[1].lower() in extensions):
l.append(os.path.join(root, name))
if(not subdirs):
while(len(dirs) > 0):
dirs.pop()
elif(not avoid_directories is None):
for d in avoid_directories:
if(d in dirs): dirs.remove(d)
return l
这种方法很方便，例如不解析.svn路径，这肯定会触发find_duplicates中的文件冲突。
欢迎反馈。
【讨论】：
@IanLee1521 有一个很好的解决方案here。它非常有效，因为它首先根据文件大小检查重复项。
#! /usr/bin/env python
# Originally taken from:
# http://www.pythoncentral.io/finding-duplicate-files-with-python/
# Original Auther: Andres Torres
# Adapted to only compute the md5sum of files with the same size
import argparse
import os
import sys
import hashlib
def find_duplicates(folders):
"""
Takes in an iterable of folders and prints & returns the duplicate files
"""
dup_size = {}
for i in folders:
# Iterate the folders given
if os.path.exists(i):
# Find the duplicated files and append them to dup_size
join_dicts(dup_size, find_duplicate_size(i))
else:
print('%s is not a valid path, please verify' % i)
return {}
print('Comparing files with the same size...')
dups = {}
for dup_list in dup_size.values():
if len(dup_list) > 1:
join_dicts(dups, find_duplicate_hash(dup_list))
print_results(dups)
return dups
def find_duplicate_size(parent_dir):
# Dups in format {hash:[names]}
dups = {}
for dirName, subdirs, fileList in os.walk(parent_dir):
print('Scanning %s...' % dirName)
for filename in fileList:
# Get the path to the file
path = os.path.join(dirName, filename)
# Check to make sure the path is valid.
if not os.path.exists(path):
continue
# Calculate sizes
file_size = os.path.getsize(path)
# Add or append the file path
if file_size in dups:
dups[file_size].append(path)
else:
dups[file_size] = [path]
return dups
def find_duplicate_hash(file_list):
print('Comparing: ')
for filename in file_list:
print(' {}'.format(filename))
dups = {}
for path in file_list:
file_hash = hashfile(path)
if file_hash in dups:
dups[file_hash].append(path)
else:
dups[file_hash] = [path]
return dups
# Joins two dictionaries
def join_dicts(dict1, dict2):
for key in dict2.keys():
if key in dict1:
dict1[key] = dict1[key] + dict2[key]
else:
dict1[key] = dict2[key]
def hashfile(path, blocksize=65536):
afile = open(path, 'rb')
hasher = hashlib.md5()
buf = afile.read(blocksize)
while len(buf) > 0:
hasher.update(buf)
buf = afile.read(blocksize)
afile.close()
return hasher.hexdigest()
def print_results(dict1):
results = list(filter(lambda x: len(x) > 1, dict1.values()))
if len(results) > 0:
print('Duplicates Found:')
print(
'The following files are identical. The name could differ, but the'
' content is identical'
)
print('___________________')
for result in results:
for subresult in result:
print('\t\t%s' % subresult)
print('___________________')
else:
print('No duplicate files found.')
def main():
parser = argparse.ArgumentParser(description='Find duplicate files')
parser.add_argument(
'folders', metavar='dir', type=str, nargs='+',
help='A directory to parse for duplicates',
)
args = parser.parse_args()
find_duplicates(args.folders)
if __name__ == '__main__':
sys.exit(main())
【讨论】：
import hashlib
import os
import sys
from sets import Set
def read_chunk(fobj, chunk_size = 2048):
""" Files can be huge so read them in chunks of bytes. """
while True:
chunk = fobj.read(chunk_size)
if not chunk:
return
yield chunk
def remove_duplicates(dir, hashfun = hashlib.sha512):
unique = Set()
for filename in os.listdir(dir):
filepath = os.path.join(dir, filename)
if os.path.isfile(filepath):
hashobj = hashfun()
for chunk in read_chunk(open(filepath,'rb')):
hashobj.update(chunk)
# the size of the hashobj is constant
# print "hashfun: ", hashfun.__sizeof__()
hashfile = hashobj.hexdigest()
if hashfile not in unique:
unique.add(hashfile)
else:
os.remove(filepath)
try:
hashfun = hashlib.sha256
remove_duplicates(sys.argv[1], hashfun)
except IndexError:
print """Please pass a path to a directory with
duplicate files as a parameter to the script."""
【讨论】：
【讨论】：
filecmp 非常适合检查少量文件。如果你必须处理更大的数字，它可能会相当慢。使用 filecmp 检查大小相同的 n 文件是否存在重复文件可能需要打开并（部分）读取每个文件 n-1 次，而散列只需要一次。
为了安全（如果出现问题，自动删除它们可能会很危险！），这是我使用的，基于@zalew 的回答。
还请注意，md5 sum 代码与@zalew 的代码略有不同，因为他的代码生成了太多错误的重复文件（这就是为什么我说自动删除它们很危险！）。
import hashlib, os
unique = dict()
for filename in os.listdir('.'):
if os.path.isfile(filename):
filehash = hashlib.md5(open(filename, 'rb').read()).hexdigest()
if filehash not in unique:
unique[filehash] = filename
else:
print filename + ' is a duplicate of ' + unique[filehash]
【讨论】：
我找到了一个 100% 有效的代码，用于在文件夹中递归删除重复文件。只需将 clean 方法中的文件夹名称替换为您的文件夹名称即可。
import time
import os
import shutil
from hashlib import sha256
class Duplython:
def __init__(self):
self.home_dir = os.getcwd()
self.File_hashes = []
self.Cleaned_dirs = []
self.Total_bytes_saved = 0
self.block_size = 65536
self.count_cleaned = 0
def welcome(self) -> None:
print('******************************************************************')
print('**************** DUPLYTHON ****************************')
print('********************************************************************\n\n')
print('---------------- WELCOME ----------------------------')
time.sleep(3)
print('\nCleaning .................')
return None
def generate_hash(self, Filename: str) -> str:
Filehash = sha256()
try:
with open(Filename, 'rb') as File:
fileblock = File.read(self.block_size)
while len(fileblock) > 0:
Filehash.update(fileblock)
fileblock = File.read(self.block_size)
Filehash = Filehash.hexdigest()
return Filehash
except:
return False
def clean(self) -> None:
all_dirs = [path[0] for path in os.walk('E:\\songs')]
for path in all_dirs:
os.chdir(path)
All_Files = [file for file in os.listdir() if os.path.isfile(file)]
for file in All_Files:
filehash = self.generate_hash(file)
if not filehash in self.File_hashes:
if filehash:
self.File_hashes.append(filehash)
# print(file)
else:
byte_saved = os.path.getsize(file)
self.count_cleaned += 1
self.Total_bytes_saved += byte_saved
os.remove(file)
filename = file.split('/')[-1]
print(filename, '.. cleaned ')
os.chdir(self.home_dir)
def cleaning_summary(self) -> None:
mb_saved = self.Total_bytes_saved / 1048576
mb_saved = round(mb_saved, 2)
print('\n\n--------------FINISHED CLEANING ------------')
print('File cleaned : ', self.count_cleaned)
print('Total Space saved : ', mb_saved, 'MB')
print('-----------------------------------------------')
def main(self) -> None:
self.welcome()
self.clean()
self.cleaning_summary()
#
# if __name__ == '__main__':
# App = Duplython()
# App.main()
def dedupe_bing_images():
App = Duplython()
App.main()
return True
dedupe_bing_images()
【讨论】：