将嵌套列表转换为字典，其中列表的第一个元素是字典的键

Question

I have list ,

[['1', '4.00', 'A'],
['1', '5.00', 'B'],
['2', '4.00', 'V'],
['1', '12.00', 'C'],
['3', '4.00', 'R']]

How can I convert this list to,

{'1': [{'total': 21}, {'data': [['A'], ['B'], ['C']]}]}
{'2': [{'total': 4}, {'data': ['C']}]}
{'3':....}

Answer 1

First of all we sort the data which would sort the nested lists based upon the initial elements and hence we get nested list with the elements sorted on the first index of list inside the nested list, then we simply groupby() them on the first element.

import itertools

a= [['1', '4.00', 'A'],
   ['1', '5.00', 'B'],
   ['2', '4.00', 'V'],
   ['1', '12.00', 'C'],
   ['3', '4.00', 'R'],
]

a.sort()

dictionary = {}
group = itertools.groupby(a, key = lambda x:x[0])
for k,g in group:
   ans = 0
   alphabets = []
   for i in g:
      ans+=(float(i[1]))
      alphabets.append([i[2]])
   dictionary[k] = [{'total':ans}, {'date':alphabets}]

print dictionary

>>> {'1': [{'total': 21.0}, {'date': [['C'], ['A'], ['B']]}], '3': [{'total': 4.0}, {'date': [['R']]}], '2': [{'total': 4.0}, {'date': [['V']]}]}