Question

我有超过5000个文本文件（也是csv格式），每个文件都有几百行。

在特定短语之上的所有内容，“城市”都是不必要的，我需要它下面的所有内容，有没有办法（python或批处理）删除所有内容？

Answer 1

我爱 python。但有时，sed也很有用：

sed -n '/City/,$p' file_with_city > new_file_with_city_on_first_line

Answer 2

一种算法就是：

从文件中读取，直至遇到文本“City”
以写入模式打开第二个文件
从第一个文件流到第二个
关闭两个文件
将第二个文件移至先前由第一个

虽然可以截断文件以在某个点之后删除内容，但是在某个点之前无法使用内容对其进行大小调整。你可以通过反复寻找来回使用单个文件，但这可能不值得。

如果文件足够小，你可以将整个第一个文件读入内存，然后将你想要的部分写回同一个磁盘文件。

Answer 3

Python中的

sed -i -n '/City/,$p' file1 file2 etc模拟：

#!/usr/bin/env python
import fileinput

copy = False
for line in fileinput.input(inplace=True): # edit files inplace
    if fileinput.isfirstline() or not copy: # reset `copy` flag for next file
       copy = "City" in line
    if copy:
       print line, # copy line

用法：

$ ./remove-before-city.py file1 file2 etc

此解决方案会修改在命令行中提供的文件。

Answer 4

# Use a context manager to make sure the files are properly closed.
with open('in.csv', 'r') as infile, open('out.csv', 'w') as outfile:
    # Read the file line by line...
    for line in infile:
        # until we have a match.
        if "City" in line:
            # Write the line containing "City" to the output.
            # Comment this line out if you don't want to include it.
            outfile.write(line)

            # Read the rest of the input in one go and write it
            # to the output. If you file is really big you might
            # run out of memory doing this and have to break it
            # into chunks.
            outfile.write(infile.read())

            # Our work here is done, quit the loop.
            break

Answer 5

def removeContent(file, word, n=1, removeword=False):
    with open(fname, "r") as file:
        if removeword:
            content = ''.join(file.read().split(word, n)[n])
        else:
            content = word + ''.join(file.read().split(word, n)[n])
    with open(fname, "w") as file:
        file.write(content)

for fname in filenames:
    removeContent(fname)

参数说明：

n告诉我们您要将其用于删除的单词出现。默认情况下为n = 1，因此它会在FIRST发生之前删除所有内容。要在第五个city之前删除evertything，请使用removeContent(fname, "city", 5)调用该函数。

file显然代表您要编辑的文件的名称

word是您要用于删除的字词，在您的情况下，它将是city

removeword告诉他们保留这个词，只删除它之前的文字，或者是否也删除这个词本身。

Answer 6

import os

for file in os.listdir("."):
    infile = open(file, 'rb')
    line = infile.readline()
    # Sequential read is easy on memory if the file is huge.
    while line != '' and not 'City' in line:
        line = infile.readline()     # skip all lines till 'City' line
    # Process the rest of the file after 'City'
    if 'City' in line:
        print line     # prints to stdout (or redirect to outfile)
    while line != '' :
        line = infile.readline()
        print line

如何删除文本文件中关键短语之前的所有内容？

6 个答案: