如何在读取 Python 中的文件行时不创建无限循环？

Question

I've looked around, but can't figure out why my 3rd function, info_count(), is running on an infinite loop:

def error_statement():
    errorLog = open("error_log.txt", "r")
    for line in errorLog:
        if "[error]" in line:
            print(line)

def statistics_statement():
    errorLog = open("error_log.txt", "r")
    for line in errorLog:
        if "statistics" in line:
            print(line)

def info_count():
    errorLog = open("error_log.txt", "r")
    count = 0
    for line in errorLog:
        if "[info]" in line:
            count += 1
        print(count)

error_statement()
statistics_statement()
info_count()

The first two return the proper results and ends. But my count keeps looping and I don't see why it doesn't break at the end of the run.

In addition, once I get that count, I want to later print those lines out, but only a specific section ie the IP address, which may vary on each line that returns "[info]". Please advise.

Answer 1

Do you mean why the program prints count many time? If so, you should remove an indent:

def info_count():
    errorLog = open("error_log.txt", "r")
    count = 0
    for line in errorLog:
        if "[info]" in line:
            count += 1
    print(count)

Answer 2

For the IP addresses (requested in the comments):

import re

def ip():
    error_log = open('error_log.txt','r')
    ip = re.findall('\[client .*?\]', error_log.read())
    print('\n'.join([x[8:-1] for x in ip]))
ip()

Square brackets are special characters, so we want to tell python that we only want them as part of the string, To do that, right before the special character, we put a backslash.

The * is to tell python we want all the characters between [client and ] .

The . dot tells the program that we accept any character besides newlines.

The ? is to tell python not to be greedy .

For example, say this is our string: 'Hello, my name is Ann. What is your name?' 'Hello, my name is Ann. What is your name?'

We want to find all the characters between 'm' and 'n' .

If our program is greedy, it will give us ['y name is Ann. What is your '] ['y name is Ann. What is your '] , if not greedy, ['y ', 'e is A'] .