如何在循环内部根据键合并字典

Question

所以我有一个嵌套字典列表，我想创建一个字典。几天前我遇到了类似的问题，我认为解决方案非常相似，但我似乎无法掌握它。这是原始列表：list = [{'user': 'nikos', 'area': 'Africa', 'keywords': 'Kenya$Egypt'},{'user': 'nikos', 'area': 'Europe', 'keywords': 'Brexit'},{'user': 'maria', 'area': 'US & Canada', 'keywords': 'New York'},{'user': 'maria', 'area': 'Latin America ', 'keywords': 'Brazil'}]我想这样创建字典：dictionary = {'user': 'nikos', 'areas': {'Africa': ['Kenya', 'Egypt'],'Europe': ['Brexit']}1）我设法创建了这些：{'user': 'nikos', 'areas': {'Africa': ['Kenya', 'Egypt']}}{'user': 'nikos', 'areas': {'Europe': ['Brexit']}}但我不能越过这一点并在我的循环中合并到一个字典中（根据我的尝试，我得到了各种错误）2）我也尝试过这样的字典理解：dict_1 = {'user': username, 'areas': {new_profile.get('areas') for x in new_profs}}这当然是不正确的，但我想知道我是否接近正确的username = 'nikos'user = {}for i in list:  if i['user'] == username:     new_profile = {'user': username, 'areas': {i['area']: i['keywords'].split('$')}}    if new_profile:        new_profs = []        new_profs.append(new_profile)

Answer 1

你走在正确的道路上。基本上一旦你得到new_profs你需要单独处理合并。像这样的东西：

userlist = [{'user': 'nikos', 'area': 'Africa', 'keywords': 'Kenya$Egypt'},

{'user': 'nikos', 'area': 'Europe', 'keywords': 'Brexit'},

{'user': 'maria', 'area': 'US & Canada', 'keywords': 'New York'},

{'user': 'maria', 'area': 'Latin America ', 'keywords': 'Brazil'}]

username = 'nikos'

user = {}

new_profs = []

for i in userlist:

  if i['user'] == username:

    new_profile = {'user': username, 'areas': {i['area']: i['keywords'].split('$')}}

    if new_profile:

        new_profs.append(new_profile)

print new_profs

'''will give you 

[{'user': 'nikos', 'areas': {'Africa': ['Kenya', 'Egypt']}}, {'user': 'nikos', 'areas': {'Europe': ['Brexit']}}]'''

#get all unique users

userset = set([x['user'] for x in new_profs])

merged_profs = []

#for each unique user, go through all the new_profs and merge all of them into one dict

for user in userset:

    merged_dict = {}

    for userprof in new_profs:

        if userprof['user'] == user:

            if merged_dict:

                new_areas = merged_dict.get('areas')

                # you might need to tweak this for your needs. For example, if you want all Europe countries

                # in one dict. Better pull this out into method and add logic accordingly

                new_areas.update(userprof['areas'])

                merged_dict['areas'] = new_areas

            else:

                merged_dict.update(userprof)

    merged_profs.append(merged_dict)

print merged_profs

#gives you [{'user': 'nikos', 'areas': {'Europe': ['Brexit'], 'Africa': ['Kenya', 'Egypt']}}]

Answer 2

我会这样做：

#!/usr/bin/python3

l = [

     {'user': 'nikos', 'area': 'Africa', 'keywords': 'Kenya$Egypt'},

     {'user': 'nikos', 'area': 'Europe', 'keywords': 'Brexit'},

     {'user': 'maria', 'area': 'US & Canada', 'keywords': 'New York'},

     {'user': 'maria', 'area': 'Latin America ', 'keywords': 'Brazil'}

    ]

# The end result

result = list()

# First extract the names from the dict and put them in

# a set() to remove duplicates.

for name in set([x["user"] for x in l]):

    # define the types that hold your results

    user_dict = dict()

    area_dict = dict()

    keyword_list = list()

    for item in l:

       if item["user"] == name:

            # Get the keywords for a given entry in "l"

            # and place them in a dictionary with the area keyword from "l"

            keyword_list = item["keywords"].split("$")

            area_dict[item["area"]] = keyword_list

    # Pack it all together in the result list.

    user_dict["name"] = name

    user_dict["areas"] = area_dict

    result.append(user_dict)

这使：

[

   {'name': 'maria', 'areas': {'US & Canada': ['New York'], 'Latin America ': ['Brazil']}},

   {'name': 'nikos', 'areas': {'Africa': ['Kenya', 'Egypt'], 'Europe': ['Brexit']}}

]