删除python中的特定字符串和特定空行

Question

我正在删除文本文件中的特定字符串和空行，这是我之前的问题的后续内容...我参考了我们的 SO 专家的一些示例和解决方案...通过删除字符串效果很好，但是不是空行。为了便于理解，我在这里强调了这个问题。

文本文件的某些部分包含 stringA、stringB 和 stringC 行以及它下面的空行，只删除它下面的单行。

line0
line1      stringAxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line2                stringBxxxxxxxxxxxxxxxxxxxxxxx
line3        stringCxxxxxxxxxxxxxxxxxxx 
line4
line5
line6  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line7  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line8  
line9  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line10 textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line11               stringBxxxxxxxxxxxxxxxxxxxxxxx
line12       stringCxxxxxxxxxxxxxxxxxxx  
line13
line14
line15  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line16  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line17 
line18  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line19  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line20
line21  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line22  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line23 
line24  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line25  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line26               stringBxxxxxxxxxxxxxxxxxxxxxxx
line27       stringCxxxxxxxxxxxxxxxxxxx  
line28
line29
line30  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line31  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line32  

在这种情况下，删除任何包含 stringA、stringB、stringC 和其后一行的行。例如上面，删除第 1,2,3,4 行删除第 11,12,13 行删除第 26,27,28 行

我尝试过使用 strip() 但它删除了所有空行。这是我使用的脚本，它确实删除了所有包含 stringA、stringB 和 stringC 的行。

filename = 'raw.txt'
with open(filename, 'r') as fin:
    lines = fin.readlines()
with open('clean.txt', 'w') as fout:
   for line in lines:
        if not re.match(r"\s+(stringA|stringB|stringC)", line):
            fout.write(line)

预期输出

line0
line5
line6  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line7  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line8  
line9  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line10 textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line14
line15  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line16  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line17 
line18  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line19  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line20
line21  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line22  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line23 
line24  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line25  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line29
line30  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line31  textxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
line32  

感谢您的帮助和善意的帮助。谢谢。

Answer 1

我很确定这不是最佳答案，但“类似标志”的方法有效：

import re
filename = 'raw.txt'
with open(filename, 'r') as fin:
    lines = fin.readlines()

flag = 0

with open('clean.txt', 'w') as fout:
    for line in lines:
        if not re.match(r'.*(stringA|stringB|stringC)', line):
            if not flag:
                fout.write(line)
            flag = 0
        else:
            flag = 1

希望对你有帮助

Answer 2

优化方案：

with open('raw.txt', 'r') as fin, open('clean.txt', 'w') as fout:
    string_c_pat = re.compile(r'\s+stringC')
    pat = re.compile(r"\s+(stringA|stringB|stringC)")

    for line in fin:    # traversing file as iterator 
        if string_c_pat.match(line):
            next(fin)   # skip `stringC` line and jump to next line
        if not pat.match(line):
            fout.write(line)

---

使用re.compile() 并保存生成的正则表达式 使用表达式时，对象的重用效率更高 在一个程序中多次。