如何使用python regex从服务器日志文件中提取IP地址？

Question

I am currently getting started with python. I have a server log file for the pages I visited over a period of time.

How do I write a python program to find out which IP address was visited most? Will I have to use dictionary? I have done this but I am not sure how to use regex to fetch IP addresses.

import re

openFile = open('text.txt', "r")

readLines = openFile.read()
# pat = re.compile("^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}$")
wordfreq = {}

for word in readLines.split():
    if word not in wordfreq:
        wordfreq[word] = 1
    else:
        wordfreq[word] += 1

print(wordfreq)

# wordList = [(v,k) for k,v in wordfreq.items()]
# wordList.sort(reverse=True)
# 
# print(wordList)

PS: I don't want to use counter from python module. I am figuring out to do this with dictionary.

Answer 1

Using Regex and Counter

Demo:

import re
from collections import Counter
s = """www.google.com : 255.111.111.111

-some random stuff-

www.facebook.com : 255.222.222.222

-some random stuff-

www.google.com : 255.111.111.111

-some random stuff-

www.google.com : 255.111.111.111

-some random stuff-
"""

ips = re.findall("www\.[A-za-z]+\.[a-z]+\s+\:\s+(.*$)", s, flags=re.MULTILINE)
print(Counter(ips).most_common(1))

Output:

[('255.111.111.111', 3)]

Answer 2

Another way to extract the IP addresses in addition to what Rakesh posted earlier:

import re

pattern = '\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}'
finalIP = re.findall(pattern, s)

For the counter, refer to his answer. I just posted a different regex!

Answer 3

To find out which IP address was visited most and this shows in ascending order. You can take 1st IP as the most visited one.

import re
import operator

openFile = open("text.txt", "r").readlines()

wordfreq = {}

for line in openFile:
    ipAddr = line.split(" ")[0]
    if ipAddr not in wordfreq:
        wordfreq[ipAddr] = 0

    wordfreq[ipAddr] += 1

#print(wordfreq)

# sorting the dict
sorted_ips = dict(
    sorted(wordfreq.items(), key=operator.itemgetter(1), reverse=True))


for ipAddr, count in sorted_ips.items():
    print("{} : {}".format(ipAddr, count))