如何搜索和替换文件中的文本?

如何使用python3搜索和替换文件中的文本?

这是我的代码:

import os
import sys
import fileinput

print ("Text to search for:")
textToSearch = input( "> " )

print ("Text to replace it with:")
textToReplace = input( "> " )

print ("File to perform Search-Replace on:")
fileToSearch  = input( "> " )
#fileToSearch = 'D:\dummy1.txt'

tempFile = open( fileToSearch, 'r+' )

for line in fileinput.input( fileToSearch ):
    if textToSearch in line :
        print('Match Found')
    else:
        print('Match Not Found!!')
    tempFile.write( line.replace( textToSearch, textToReplace ) )
tempFile.close()


input( '\n\n Press Enter to exit...' )

输入文件:

hi this is abcd hi this is abcd
This is dummy text file.
This is how search and replace works abcd

当我在上面的输入文件中搜索并将“ram”替换为“abcd”时，它就像一个咒语。但当我反过来做，即替换'abcd'由'ram'，一些垃圾字符被留在最后。

将'abcd'替换为'ram'

hi this is ram hi this is ram
This is dummy text file.
This is how search and replace works rambcd

当前回答

正如Jack Aidley发布的和J.F. Sebastian指出的那样，这个代码是行不通的:

 # Read in the file
filedata = None
with file = open('file.txt', 'r') :
  filedata = file.read()

# Replace the target string
filedata.replace('ram', 'abcd')

# Write the file out again
with file = open('file.txt', 'w') :
  file.write(filedata)`

但这段代码将工作(我已经测试过了):

f = open(filein,'r')
filedata = f.read()
f.close()

newdata = filedata.replace("old data","new data")

f = open(fileout,'w')
f.write(newdata)
f.close()

使用此方法，fileein和fileout可以是同一个文件，因为Python 3.3将在打开进行写入时覆盖该文件。

2014-04-05 05:19:15

其他回答

我的变种，在整个文件中一次一个词。

我把它读进了记忆。

def replace_word(infile,old_word,new_word):
    if not os.path.isfile(infile):
        print ("Error on replace_word, not a regular file: "+infile)
        sys.exit(1)

    f1=open(infile,'r').read()
    f2=open(infile,'w')
    m=f1.replace(old_word,new_word)
    f2.write(m)

2013-12-15 10:19:22

def findReplace(find, replace):

    import os 

    src = os.path.join(os.getcwd(), os.pardir) 

    for path, dirs, files in os.walk(os.path.abspath(src)):

        for name in files: 

            if name.endswith('.py'): 

                filepath = os.path.join(path, name)

                with open(filepath) as f: 

                    s = f.read()

                s = s.replace(find, replace) 

                with open(filepath, "w") as f:

                    f.write(s)

2018-06-20 10:06:18

我是这样做的:

#!/usr/bin/env python3

import fileinput
import os

Dir = input ("Source directory: ")
os.chdir(Dir)

Filelist = os.listdir()
print('File list: ',Filelist)

NomeFile = input ("Insert file name: ")

CarOr = input ("Text to search: ")

CarNew = input ("New text: ")

with fileinput.FileInput(NomeFile, inplace=True, backup='.bak') as file:
    for line in file:
        print(line.replace(CarOr, CarNew), end='')

file.close ()

2017-02-16 21:26:18

正如michaelb958所指出的，不能用不同长度的数据替换现有的部分，因为这会使其余部分不合适。我不同意其他人建议你从一个文件读到另一个文件。相反，我将把文件读入内存，修复数据，然后在单独的步骤中将其写入相同的文件。

# Read in the file
with open('file.txt', 'r') as file :
  filedata = file.read()

# Replace the target string
filedata = filedata.replace('abcd', 'ram')

# Write the file out again
with open('file.txt', 'w') as file:
  file.write(filedata)

除非你有一个巨大的文件要处理，它太大了，无法一次性加载到内存中，或者你担心如果在向文件写入数据的第二步过程中中断，可能会导致数据丢失。

2013-06-17 06:29:50

我已经把这个作为一个课程的练习:打开文件，找到并替换字符串，并写入一个新文件。

class Letter:

    def __init__(self):

        with open("./Input/Names/invited_names.txt", "r") as file:
            # read the list of names
            list_names = [line.rstrip() for line in file]
            with open("./Input/Letters/starting_letter.docx", "r") as f:
                # read letter
                file_source = f.read()
            for name in list_names:
                with open(f"./Output/ReadyToSend/LetterTo{name}.docx", "w") as f:
                    # replace [name] with name of the list in the file
                    replace_string = file_source.replace('[name]', name)
                    # write to a new file
                    f.write(replace_string)


brief = Letter()

2021-02-15 16:52:31

如何搜索和替换文件中的文本?

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