返回两个文件之间不同的行(Python)

2019年8月4日 165次阅读

我有两个文件,每行有数万行,output1.txt和output2.txt.我想迭代这两个文件并返回两者之间不同的行的行(和内容).它们大致相同,这就是为什么我找不到差异(filecmp.cmp返回false). 最佳答案 你可以这样做：

import difflib, sys

tl=100000    # large number of lines

# create two test files (Unix directories...)

with open('/tmp/f1.txt','w') as f:
    for x in range(tl):
        f.write('line {}\n'.format(x))

with open('/tmp/f2.txt','w') as f:
    for x in range(tl+10):   # add 10 lines
        if x in (500,505,1000,tl-2):
            continue         # skip these lines
        f.write('line {}\n'.format(x))        

with open('/tmp/f1.txt','r') as f1, open('/tmp/f2.txt','r') as f2:
    diff = difflib.ndiff(f1.readlines(),f2.readlines())    
    for line in diff:
        if line.startswith('-'):
            sys.stdout.write(line)
        elif line.startswith('+'):
            sys.stdout.write('\t\t'+line)

打印(400毫秒)：

- line 500
- line 505
- line 1000
- line 99998
        + line 100000
        + line 100001
        + line 100002
        + line 100003
        + line 100004
        + line 100005
        + line 100006
        + line 100007
        + line 100008
        + line 100009

如果您想要行号,请使用枚举：

with open('/tmp/f1.txt','r') as f1, open('/tmp/f2.txt','r') as f2:
    diff = difflib.ndiff(f1.readlines(),f2.readlines())    
    for i,line in enumerate(diff):
        if line.startswith(' '):
            continue
        sys.stdout.write('My count: {}, text: {}'.format(i,line))
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