python3：set 和 itertools.groupby 产生不同的结果？ [复制]

Posted 2023-02-25

【中文标题】python3：set 和 itertools.groupby 产生不同的结果？ [复制]

【英文标题】：python3: set and itertools.groupby yielding different outcomes? [duplicate]

【发布时间】：2019-11-21 11:14:49

【问题描述】：

我想使用IPWhois 解析一些 Apache 访问日志。

我想根据asn_description 字段对IPWhois 结果进行分组。

以下sn-p中的set和itertools.groupby()是不是会产生不同的结果？

descs = set()

with open(RESULTSFILE, 'a+') as r:
    for description, items in groupby(results, key=lambda x: x['asn_description']):
        print('ASN Description: ' + description)
        descs.add(description)

print(descs)

例如

ASN Description: GOOGLE - Google LLC, US
ASN Description: AVAST-AS-DC, CZ
ASN Description: FACEBOOK - Facebook, Inc., US
ASN Description: AVAST-AS-DC, CZ
ASN Description: AMAZON-AES - Amazon.com, Inc., US
ASN Description: FACEBOOK - Facebook, Inc., US
ASN Description: AMAZON-02 - Amazon.com, Inc., US
ASN Description: AMAZON-02 - Amazon.com, Inc., US
ASN Description: GOOGLE - Google LLC, US
ASN Description: GOOGLE-2 - Google LLC, US
ASN Description: AMAZON-02 - Amazon.com, Inc., US
'FACEBOOK - Facebook, Inc., US', 'AVAST-AS-DC, CZ', 'AMAZON-AES - Amazon.com, Inc., US', 'GOOGLE-2 - Google LLC, US', 'GOOGLE - Google LLC, US', 'AMAZON-02 - Amazon.com, Inc., US',

【问题讨论】：

Set 会返回唯一的值，groupby 只返回连续的唯一值

【参考方案1】：

将您的代码更改为以下内容并尝试。如果您不需要items，则可以使用_ 将其从for 循环中删除。

import itertools
descs = dict()

with open(RESULTSFILE, 'a+') as r:
    for i, (description, items) in enumerate(itertools.groupby(results, key=lambda x: x['asn_description'])):
        print('ASN Description: ' + description)
        descs.update(i: description)

print(descs)