Question

我想找一个短语：＆＃34;删除这个＆＃34;。我想只保留两次出现的短语，并删除其他所有内容。

text.text.text.text
text.text.text.text
text.text.text.text
text.text.text.text
delete this
text.text.text.text
text.text.text.text
text.text.text.text
delete this
text.text.text.text
text.text.text.text

这是我目前的代码：

import urllib2
import unicodecsv as csv
import os
import sys
import io
import time
import datetime
import pandas as pd
from bs4 import BeautifulSoup
import sys
import re

def to_2d(l,n):
    return [l[i:i+n] for i in range(0, len(l), n)]

f = open('air.txt', 'r')
x = f.readlines()

filename=r'output.csv'

resultcsv = open(filename,"wb")
output = csv.writer(resultcsv, delimiter=';',quotechar = '"', quoting=csv.QUOTE_NONNUMERIC, encoding='latin-1')

maindatatable = to_2d(x, 4)
    if 'delete this' in maindatatable.text:
                stop = 1
                break

print maindatatable
output.writerows(maindatatable)

resultcsv.close()

Answer 1

您可以使用str.split：

with open('air.txt', 'r') as f:
    x = f.read()

req_text = x.split('delete this')[1: -1]

data = []
for text in req_text:
    for line in text.strip().splitlines():
        data.append([line])

要写入csv文件，只需打开它并拨打writer.writerows：

with open('output.csv', "wb") as f
    output = csv.writer(f, delimiter=';',quotechar = '"', quoting=csv.QUOTE_NONNUMERIC, encoding='latin-1')
    output.writerows(data)

将其保存到文件中：

text.text.text.text
text.text.text.text
text.text.text.text

使用delete代替delete this：

req_text = x.split('delete')[1: -1]

data = []
for text in req_text:
    text = text.split('\n', 1)[1]
    for line in text.strip().splitlines():
        data.append([line])

Answer 2

这是一个带开关的基本结构。即使有多个delete_this对，它也应该有效：

read = False
with open('data.txt') as txt:
    for line in txt:
        if line.strip() == 'delete this':
            read = not read
        elif read:
            print line,

data.txt为：

text.text.text.text1
text.text.text.text2
text.text.text.text3
text.text.text.text4
delete this
text.text.text.text5
text.text.text.text6
text.text.text.text7
delete this
text.text.text.text8
text.text.text.text9

输出：

text.text.text.text5
text.text.text.text6
text.text.text.text7

Answer 3

我现在要假设分隔符是完整的行。这是达到你想要的一种方式：

import sys
delimiter = "delete this\n"
result = []
with open('air.txt', 'r') as inf:
    for line in inf:
        if line == delimiter:
            break
    else:
        sys.exit("opening delimiter missing")
    for line in inf:
        if line != delimiter:
            result.append(line)
        else:
            break
    else:
        sys.exit("closing delimiter missing")

只有在循环中没有执行else语句时，才会执行附加到for语句的break子句。这可以确保各种奇怪的文件末尾条件不会弄乱您的逻辑。

with语句是一种使文件可用的便捷方式，并确保无论发生什么，它都会在使用后正确关闭。

result列表可以转换为带有简单构造的字符串：

output = "".join(result)

如何在文本文件中查找短语并在之前/之后删除？

3 个答案: