使用Python删除匹配正则表达式的所有行

Question

我试图删除我的正则表达式匹配的所有行(正则表达式只是寻找任何包含yahoo的行).每个匹配都在它自己的行上,因此不需要多行选项.

这就是我到目前为止......

import re
inputfile = open('C:\\temp\\Scripts\\remove.txt','w',encoding="utf8")

inputfile.write(re.sub("\[(.*?)yahoo(.*?)\n","",inputfile))

inputfile.close()

我收到以下错误:

回溯(最近调用最后一次):第170行,在子返回_compile(模式,标志).sub(repl,string,count)TypeError:期望的字符串或缓冲区

Answer 1

fileinput如果要修改原始文件,请使用模块:

import re
import fileinput
for line in fileinput.input(r'C:\temp\Scripts\remove.txt', inplace = True):
   if not re.search(r'\byahoo\b',line):
      print line,

Answer 2

这是@Ashwini Chaudhary的答案的Python 3变体,删除包含pattern来自给定的正则表达式的所有行filename:

#!/usr/bin/env python3
"""Usage: remove-pattern <pattern> <file>"""
import fileinput
import re
import sys

def main():
    pattern, filename = sys.argv[1:] # get pattern, filename from command-line
    matched = re.compile(pattern).search
    with fileinput.FileInput(filename, inplace=1, backup='.bak') as file:
        for line in file:
            if not matched(line): # save lines that do not match
                print(line, end='') # this goes to filename due to inplace=1

main()

它假定locale.getpreferredencoding(False) == input_file_encoding否则可能会在非ASCII字符打破.

无论当前语言环境是什么,或者对于具有不同编码的输入文件,使其工作:

#!/usr/bin/env python3
import os
import re
import sys
from tempfile import NamedTemporaryFile

def main():
    encoding = 'utf-8'
    pattern, filename = sys.argv[1:]
    matched = re.compile(pattern).search
    with open(filename, encoding=encoding) as input_file:
        with NamedTemporaryFile(mode='w', encoding=encoding,
                                dir=os.path.dirname(filename),
                                delete=False) as outfile:
            for line in input_file:
                if not matched(line):
                    print(line, end='', file=outfile)
    os.replace(outfile.name, input_file.name)

main()

Answer 3

您必须阅读文件尝试类似：

import re
inputfile = open('C:\\temp\\Scripts\\remove.txt','w',encoding="utf8")

inputfile.write(re.sub("\[(.*?)yahoo(.*?)\n","",inputfile.read()))

file.close()
outputfile.close()