python filecmp.dircmp实现递归比对两个目录的方法

脚本专栏 2024/11/8 佚名

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使用python filecmp模块的dircmp类可以很方便的比对两个目录，dircmp的用法已经有很多文章介绍，不再赘述。

可以help(filecmp.dircmp)查看帮助信息，其中提到的x.report()、x.report_partial_closure()，都只能打印两目录一级子目录的比较信息。而x.report_full_closure()可以递归打印所有子目录的比对信息，但是输出太多，大多数情况下我们可能只关心两目录的不同之处。

help(filecmp.dircmp) 摘选：            
 
 | High level usage:              
 | x = dircmp(dir1, dir2)             
 | x.report() -> prints a report on the differences between dir1 and dir2 
 |  or                 
 | x.report_partial_closure() -> prints report on differences between dir1
 |   and dir2, and reports on common immediate subdirectories.  
 | x.report_full_closure() -> like report_partial_closure,    
 |   but fully recursive.

本文编写的脚本，重点关注并实现两个目标：

2）仅输出两目录不同之处，包括文件名相同(common_files)但是文件不一致(diff_files)，以及左、右目录中独有的文件或子目录。

py脚本compare_dir.py内容如下：

# -*- coding: utf-8 -*-
"""
@desc 使用filecmp.dircmp递归比对两个目录，输出比对结果以及统计信息。
@author longfeiwlf
@date 2020-5-20
"""
 
from filecmp import dircmp
import sys
 
# 定义全局变量：
number_different_files = 0 # 文件名相同但不一致的文件数
number_left_only = 0 # 左边目录独有的文件或目录数
number_right_only = 0 # 右边目录独有的文件或目录数
 
 
def print_diff(dcmp):
 """递归比对两目录，如果有不同之处，打印出来，同时累加统计计数。"""
 global number_different_files
 global number_left_only
 global number_right_only
 for name in dcmp.diff_files:
  print("diff_file found: %s/%s" % (dcmp.left, name))
  number_different_files += 1
 for name_left in dcmp.left_only:
  print("left_only found: %s/%s" % (dcmp.left, name_left))
  number_left_only += 1
 for name_right in dcmp.right_only:
  print("right_only found: %s/%s" % (dcmp.right, name_right))
  number_right_only += 1
 for sub_dcmp in dcmp.subdirs.values():
  print_diff(sub_dcmp) # 递归比较子目录
 
 
if __name__ == '__main__':
 try:
  mydcmp = dircmp(sys.argv[1], sys.argv[2])
 except IndexError as ie:
  print(ie)
  print("使用方法：python compare_dir_cn.py 目录1 目录2")
 else:
  print("\n比对结果详情: ")
  print_diff(mydcmp)
  if (number_different_files == 0 and number_left_only == 0
    and number_right_only == 0):
   print("\n两个目录完全一致!")
  else:
   print("\n比对结果统计:")
   print("Total Number of different files is: " 
     + str(number_different_files))
   print("Total Number of files or directories only in '"
     + sys.argv[1] + "' is: " + str(number_left_only))
   print("Total Number of files or directories only in '"
     + sys.argv[2] + "' is: " + str(number_right_only))

compare_dir.py脚本使用举例: