How to change a specific word in a TXT by another

Question

I need to change the configuration of the Zabbix server that is in this directory C:\zabbix\conf\zabbix_agentd.win.conf

I need to replace the word: hostname= for hostname=192.168.1.1

I did that, but the part below the hostname I didn’t understand where to put the name to search and where to put the word that will replace it. I am using Python 3.6

import socket
import re

hostname = socket.gethostname()

with open('C:\zabbix\conf\zabbix_agentd.win.conf') as f:
    for l in f:
        s = l.split('*')
        editar = re.sub(r"\b%s\b" % s[0] , s[1], editor)

Answer 1

Your code doesn’t make much sense for what you’re asking for. You don’t need to use regular expressions for your case, and neither split. Just the replace, which is the most basic method that does this and is a function of the class str.

Also, changing the variables after reading the file in read mode does not change the file. To change the file, it is necessary to open it in writing mode (passing 'w' as a second argument from open) and write your data with write or writelines.

Suppose my hostname is 'DESKTOP-PI3R74I' and my file contains the following:

lalala
foo
DESKTOP-PI3R74I=
bar
foobar

Your code would look like this:

import socket

hostname = socket.gethostname()
print(hostname)  # 'DESKTOP-PI3R74I'

# Abrir o arquivo em modo de leitura
with open('arquivo.txt', 'r') as fd:
    txt = fd.read()  # Ler todo o arquivo

    # Substituir hostname= por hostname=192.168.1.1 em todas as 
    # ocorrências no texto lido
    txt = txt.replace(hostname + '=', hostname + '=192.168.1.1')

# Abrir o arquivo em modo de escrita
with open('arquivo.txt', 'w') as fd:
    fd.write(txt)  # Escrever texto modificado