python - 如何进行如此的操作

Question

有一个list:

[
    {'time':2016,'t':'jsaidja'},
    {'time':2016,'t':'wtfja'},
    {'time':2016,'t':'cbsasja'},
    {'time':2015,'t':'45gj'},
    {'time':2015,'t':'gt43ga'}
]

如何转换成

{
    2016:['jsaidja','wtfja','cbsasja'],
    2015:['45gj','gt43ga']
}

Answer 1

source = [
    {'time': 2016, 't': 'jsaidja'},
    {'time': 2016, 't': 'wtfja'},
    {'time': 2016, 't': 'cbsasja'},
    {'time': 2015, 't': '45gj'},
    {'time': 2015, 't': 'gt43ga'}
]

from collections import defaultdict

result = defaultdict(list)

for item in source:
    result[item['time']].append(item['t'])

print result

Answer 2

遍历一次,time相同的放在一个list里面

Answer 3

提供另外一种方法：

from itertools import groupby

source = [
    {'time': 2016, 't': 'jsaidja'},
    {'time': 2016, 't': 'wtfja'},
    {'time': 2016, 't': 'cbsasja'},
    {'time': 2015, 't': '45gj'},
    {'time': 2015, 't': 'gt43ga'}
]

result = {}
for time, g in groupby(sorted(source, key=lambda s: s['time']), key=lambda s: s['time']):
    result[time] = [e['t'] for e in g]
print result