1 #!/usr/bin/python python
 2 # -*-coding=utf-8-*-
 3 
 4 d = [
 5     {'year':2014L,'month':1L,'id':1},
 6     {'year':2014L,'month':2L,'id':2},
 7     {'year':2013L,'month':3L,'id':3},
 8     {'year':2014L,'month':1L,'id':4},
 9     {'year':2013L,'month':1L,'id':5}
10     ]
11 dd = {}
12 for x in d:
13     year  = str(x['year'])
14     month = str(x['month'])
15     data = {'id':x['id']}
16     if year in dd:
17         check = True
18         for y in dd[year]:
19             if month in y:
20                 check = False
21                 y[month].append(data)
22         if check:
23             dd[year].append({month:[data]})
24                 
25     else:
26         dd[year]=[{month:[data]}]
27 print dd

~/code/python/test $ python blog.py 
{'2014': [{'1': [{'id': 1}, {'id': 4}]}, {'2': [{'id': 2}]}], '2013': [{'3': [{'id': 3}]}, {'1': [{'id': 5}]}]}