pandas 在python中将dict转换为排序的dict
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convert a dict to sorted dict in python
提问by Code Ninja
I want to convert a dict into sorted dict in python
我想在python中将dict转换为排序的dict
data = pandas.read_csv('D:\myfile.csv')
for colname, dtype in data.dtypes.to_dict().iteritems():
if dtype == 'object':
print colname
count = data[colname].value_counts()
d = dict((str(k), int(v)) for k, v in count.iteritems())
f = dict(sorted(d.iteritems(), key=lambda item: item[1], reverse = True)[:5])
print f
m ={}
m["count"]= int(sum(count))
m["Top 5"]= f
print m
k = json.dumps(m)
print k
f = {'Gears of war 3': 6, 'Batman': 5, 'gears of war 3': 4, 'Rocksmith': 5, 'Madden': 3}
My desired Output is :
我想要的输出是：
f = {'Gears of war 3': 6, 'Batman': 5, 'Rocksmith': 5, 'gears of war 3': 4, 'Madden': 3}
k = {'count':24, 'top 5':{'Gears of war 3': 6, 'Batman': 5, 'Rocksmith': 5, 'gears of war 3': 4, 'Madden': 3}}
(in the descending order of values and the result should be a dict)
（按值的降序排列，结果应该是一个字典）
回答by K Z
You cannot sort a dictbecause dictionary has no ordering.
您不能对 a 进行排序，dict因为字典没有排序。
Instead, use collections.OrderedDict:
相反，使用collections.OrderedDict：
>>> from collections import OrderedDict
>>> d = {'Gears of war 3': 6, 'Batman': 5, 'gears of war 3': 4, 'Rocksmith': 5, 'Madden': 3}
>>> od = OrderedDict(sorted(d.items(), key=lambda x:x[1], reverse=True))
>>> od
OrderedDict([('Gears of war 3', 6), ('Batman', 5), ('gears of war 3', 4), ('Rocksmith', 5), ('Madden', 3)])
>>> od.keys()
['Gears of war 3', 'Batman', 'gears of war 3', 'Rocksmith', 'Madden']
>>> od.values()
[6, 5, 4, 5, 3]
>>> od['Batman']
5
The "order" you see in an JSON object is not meaningful, as JSON object is unordered[RFC4267].
您在 JSON 对象中看到的“顺序”没有意义，因为 JSON 对象是无序的 [ RFC4267]。
If you want meaningful ordering in your JSON, you need to use a list (that's sorted the way you wanted). Something like this is what you'd want:
如果您想在 JSON 中进行有意义的排序，则需要使用列表（按您想要的方式排序）。像这样的东西是你想要的：
{
"count": 24,
"top 5": [
{"Gears of war 3": 6},
{"Batman": 5},
{"Rocksmith": 5},
{"gears of war 3": 4},
{"Madden": 3}
]
}
Given the same dict d, you can generate a sorted list (which is what you want) by:
给定相同的 dict d，您可以通过以下方式生成排序列表（这是您想要的）：
>>> l = sorted(d.items(), key=lambda x:x[1], reverse=True)
>>> l
[('Gears of war 3', 6), ('Batman', 5), ('Rocksmith', 5), ('gears of war 3', 4), ('Madden', 3)]
Now you just pass lto m['top5']and dump it:
现在你只是传递l到m['top5']和转储：
m["Top 5"]= l
k = json.dumps(m)
