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

像这样:

def find_and_replace(file, word, replacement):
  with open(file, 'r+') as f:
    text = f.read()
    f.write(text.replace(word, replacement))

其他回答

我试过用readline代替read

with open('dummy.txt','r') as file:
    list = file.readlines()
print(f'before removal {list}')
for i in list[:]:
        list.remove(i)

print(f'After removal {list}')
with open('dummy.txt','w+') as f:
    for i in list:
        f.write(i)

你可以这样做替换

f1 = open('file1.txt', 'r')
f2 = open('file2.txt', 'w')
for line in f1:
    f2.write(line.replace('old_text', 'new_text'))
f1.close()
f2.close()

使用re.subn可以对替换过程进行更多的控制,例如将单词分成两行,区分大小写的匹配。此外,它返回匹配的数量,如果没有找到字符串,可以使用这些匹配来避免浪费资源。

import re

file = # path to file

# they can be also raw string and regex
textToSearch = r'Ha.*O' # here an example with a regex
textToReplace = 'hallo'

# read and replace
with open(file, 'r') as fd:
    # sample case-insensitive find-and-replace
    text, counter = re.subn(textToSearch, textToReplace, fd.read(), re.I)

# check if there is at least a  match
if counter > 0:
    # edit the file
    with open(file, 'w') as fd:
        fd.write(text)

# summary result
print(f'{counter} occurence of "{textToSearch}" were replaced with "{textToReplace}".')

一些正则表达式:

添加re.I标志,re.IGNORECASE的缩写形式,用于不区分大小写的匹配 对于多行替换re.subn(r'\n*'.join(textToSearch), textToReplace, fd.read())),取决于数据也'\n{,1}'。注意,在这种情况下,textToSearch必须是纯字符串,而不是正则表达式!

def word_replace(filename,old,new):
    c=0
    with open(filename,'r+',encoding ='utf-8') as f:
        a=f.read()
        b=a.split()
        for i in range(0,len(b)):
            if b[i]==old:
                c=c+1
        old=old.center(len(old)+2)
        new=new.center(len(new)+2)
        d=a.replace(old,new,c)
        f.truncate(0)
        f.seek(0)
        f.write(d)
    print('All words have been replaced!!!')
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)