如何获取列表中每个项目的计数？

Question

上下文：

我有一个程序可以解析日志文件以在我的机器上进行连接尝试。 它提取了一个 IP 地址列表，然后我想在这个信息列表上运行其他功能，特别是其中一个功能没有按预期工作。它应该计算每个国家/地区的连接尝试次数。

代码 - ip_tools.py

#!/usr/bin/python

import requests
import json
import socket

#function to get the ip address of the host user
def get_host_ipad():
    host_ip_request = requests.get("http://ipinfo.io/ip")
    return host_ip_request.text

#function to get gelocation info of a remote host
def get_rhost_geo(ipad):
    full_geo_info = {}
    rhost_ip_request = requests.get("http://ipinfo.io/%s/json" % (ipad))
    json_response = json.loads(rhost_ip_request.text)
    for value in json_response:
        full_geo_info.update({str(value) : str(json_response[value])})
    return full_geo_info

#function to return country of rhost
def get_geo_country(ipad):
    geo_info = get_rhost_geo(ipad)
    geo_country = geo_info["country"]
    return geo_country

#function to perform reverse dns lookup
def get_rhost_url(ipad):
    try:
        rhost_url = socket.gethostbyaddr(ipad)
        rhost_url = rhost_url[0]
    except Exception:
        rhost_url = 'No URL found for this ip address.'
    return rhost_url



#main function to run the code only if called directly
def Main():

#printing the options menu and taking a variable to be passed
    print '_' * 20
    print "1: Get your ip address: \n"
    print "2: Get Geolocation of an IP address: \n"
    print "3: Atempt getting URL from IP address"
    sel = raw_input("Choose an option: \n")

#if statement to control menu navigation
    if sel == '1':
        print get_host_ipad()

#calls the get_rhost_ipad function defined above on user input
    elif sel == '2':
        ipad = raw_input("Which IP address?: \n")
        print get_rhost_geo(ipad)
    elif sel == 'quit':
        quit()
    elif sel == '3':
        ipad = raw_input("Which IP address?: \n")
        print get_rhost_url(ipad)

    else:
        print "Please choose one of the other options. \n"

if __name__=="__main__":
        Main()

代码 - log_auditor.py：

import re
import ip_tools

#global variable to open kippo log in read mode

MY_LOG = open("/path/to/log", "r").read()

#function to get ip address from log file with a regular expression
def get_ips_from_log():
    re_ip_search = re.findall(r"\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b", MY_LOG)
    return re_ip_search

#function to get attempts per unique ip address
def get_ip_count():
    ip_log = get_ips_from_log()
    ip_count = [(i, ip_log.count(i)) for i in set(ip_log)]
    return ip_count


#function to get attempts per country
def get_country_count():
    ip_list = get_ips_from_log()
    get_country_count = [(ip_tools.get_geo_country(ip), ip_list.count(ip)) for ip in set(ip_list)]
    return get_country_count

#main function to only run program when called:

def Main():
    print get_country_count()

if __name__=='__main__':
    Main()

有问题的函数是这个：

#function to get attempts per country
def get_country_count():
    ip_list = get_ips_from_log()
    get_country_count = [(ip_tools.get_geo_country(ip), ip_list.count(ip)) for ip in set(ip_list)]
    return get_country_count

不幸的是，它的输出看起来像：

[('CN', 2), ('CN', 566), ('NL', 2), ('CN', 3040), ('CN', 2), ('CN', 1042), ('CN', 2), ('US', 2), ('KR', 382), ('DE', 2), ('US', 127)]

如何进一步分组？

Answer 1

使用字典记录每个国家/地区代码的总数。

from collections import defaultdict
def get_country_count():
    ip_list = get_ips_from_log()
    country_count = defaultdict(int)
    for ip in set(ip_list):
        country_count[ip_tools.get_geo_country(ip)] += ip_list.count(ip)
    return country_count

Answer 2

如果我们不触及所有其他代码，函数可以这样重写：

from collections import defaultdict

....

def get_country_count():
    country_count = defaultdict(int)
    for ip in get_ips_from_log():
        country_count[ip_tools.get_geo_country(ip)] += 1
    return country_count

或者如果使用get_geo_country花费很多：

def get_country_count():
    country_count = defaultdict(int)
    ip_list = get_ips_from_log()
    for ip in set(ip_list):
        country_count[ip_tools.get_geo_country(ip)] += ip_list.count(ip)
    return country_count

defaultdict 只是出于某种原因不要写出这样丑陋的结构：

def get_country_count():
   ....
   for ....
       country = ip_tools.get_geo_country(ip)
       if country in country_count:
           country_count[country] += ...
       else:
           country_count[country] = ...