添加键的值,并通过在Python中的词典列表中出现键对其进行排序

时间:2017-07-19 17:34:29

标签: python regex python-3.x sorting dictionary

我是Python新手,我遇到了下面需要解决的问题。 我有一个来自Apache Log的日志文件,如下所示:

[01/Aug/1995:00:54:59 -0400] "GET /images/opf-logo.gif HTTP/1.0" 200 32511
[01/Aug/1995:00:55:04 -0400] "GET /images/ksclogosmall.gif HTTP/1.0" 200 3635
[01/Aug/1995:00:55:06 -0400] "GET /images/ksclogosmall.gif HTTP/1.0" 403 298
[01/Aug/1995:00:55:09 -0400] "GET /images/ksclogosmall.gif HTTP/1.0" 200 3635
[01/Aug/1995:00:55:18 -0400] "GET /images/opf-logo.gif HTTP/1.0" 200 32511
[01/Aug/1995:00:56:52 -0400] "GET /images/ksclogosmall.gif HTTP/1.0" 200 3635

我将返回10个请求最多的对象及其传输的累积字节数。我只需要包含成功(HTTP 2xx)响应的GET请求。

因此上述日志将导致:

/images/ksclogosmall.gif 10905
/images/opf-logo.gif 65022

到目前为止,我有以下代码:

import re
from collections import Counter, defaultdict
from operator import itemgetter
import itertools
import sys

log_file = "web.log"
pattern = re.compile(
      r'\[(?P<date>[^\[\]:]+):(?P<time>\d+:\d+:\d+) (?P<timezone>[\-+]?\d\d\d\d)\] '
      + r'"(?P<method>\w+) (?P<path>[\S]+) (?P<protocol>[^"]+)" (?P<status>\d+) (?P<bytes_xfd>-|\d+)')

dict_list = []

with open(log_file, "r") as f:
    for line in f.readlines():
        if re.search("GET", line) and re.search(r'HTTP/[\d.]+"\s[2]\d{2}', line):
            try:
                log_line_data = pattern.match(line)
                path = log_line_data["path"]
                bytes_transferred = int(log_line_data["bytes_xfd"])
                dict_list.append({path: bytes_transferred})
            except:
                print("Unexpected Error: ", sys.exc_info()[0])
                raise
    f.close()

print(dict_list)

此代码打印以下字典列表。

[{'/images/opf-logo.gif': 32511}, 
{'/images/ksclogosmall.gif': 3635}, 
{'/images/ksclogosmall.gif': 3635}, 
{'/images/opf-logo.gif': 32511}, 
{'/images/ksclogosmall.gif': 3635}]

我不知道如何从这里开始得到结果:

/images/ksclogosmall.gif 10905
/images/opf-logo.gif 65022

此结果基本上是添加了对应于类似键的值,这些键按特定键在desc顺序中出现的次数排序。

注意:我尝试使用colllections.Counter但没有用,在这里我想按密钥发生的次数排序。

任何帮助都将不胜感激。

6 个答案:

答案 0 :(得分:8)

您可以使用collections.Counter和update来添加为每个对象传输的字节数:

from collections import Counter
c = Counter()
for d in dict_list:
    c.update(d)
occurrences=Counter([list(x.keys())[0] for x in dict_list])
sorted(c.items(), key=lambda x: occurrences[x[0]], reverse=True)

输出:

[('/images/ksclogosmall.gif', 10905), ('/images/opf-logo.gif', 65022)]

答案 1 :(得分:5)

首先,字典列表对这类数据没有意义。由于每个字典只有一个键值对,因此只需构建一个元组列表(如果想要更多可读性,则构建namedtuples列表)。

tuple_list.append((path, bytes_transferred))

现在,获得您想要的结果将更加直截了当。我个人使用defaultdict

from collections import defaultdict

tracker = defaultdict(list)
for path, bytes_transferred in tuple_list:
    tracker[path].append(bytes_transferred)
# {'/images/ksclogosmall.gif': [3635, 3635, 3635], '/images/opf-logo.gif': [32511, 32511]}

print([(p, sum(b)) for p, b in sorted(tracker.items(), key=lambda i: -len(i[1]))])
# [('/images/ksclogosmall.gif', 10905), ('/images/opf-logo.gif', 65022)]

答案 2 :(得分:0)

你可以循环你的dict并将值存储在一个新的dict中:

results = {}
for d in dict_list:
    for k, v in d.items():
        total = results.get(k, 0) # get previously stored value, 0 if none
        results[k] = total + v

答案 3 :(得分:0)

这可能不是最优雅的解决方案,但它会起作用:

freq = {}
with open('test.txt') as f:
    lines = f.read().splitlines()

    for line in lines:
        if 'GET' in line and 'HTTP' in line and '200' in line:
            path = line.split()[3]
            occur = int(line.split()[-1])
            freq[path] = freq.get(path, 0) + occur

frequency = {k: v for k, v in sorted(freq.items(), key=lambda x: x[1])}

因此,对于您提供的日志片段:

print(frequency)
>>> {'/images/ksclogosmall.gif': 10905, '/images/opf-logo.gif': 65022}

答案 4 :(得分:0)

另一个选项,两行

....
path = log_line_data["path"]
if [x for x in range(len(dict_list)) if path in dict_list[x].keys()]:
    continue

输出

[{'/images/opf-logo.gif': 32511}, {'/images/ksclogosmall.gif': 3635}]

答案 5 :(得分:0)

如果你想崩溃

[{'/images/opf-logo.gif': 32511}, 
{'/images/ksclogosmall.gif': 3635}, 
{'/images/ksclogosmall.gif': 3635}, 
{'/images/opf-logo.gif': 32511}, 
{'/images/ksclogosmall.gif': 3635}]

进入字典并使用相同的键总计值:

  1. 创建一个新的空字典
  2. 遍历每个词典,检查新词典中是否存在该词
  3. 如果密钥(文件路径)不存在,请将其复制
  4. 如果存在,请添加值
  5. ```

    total = {}
    
    for d in all:
        for k, v in d.items():
                 if k in total:
                         total[k] += v
                 else:
                         total[k] = v
    
    print(total)
    {'/images/opf-logo.gif': 65022, '/images/ksclogosmall.gif': 10905}