=============================== RESTART: Shell ===============================
>>> import time
>>> from contextlib import contextmanager
>>> @contextmanager
def get_time():
	start = time.time()
	yield
	end = time.time()
	print(end-start)

	
>>> l = [['id0', 'pyt'], ['id0', 'hon'], ['id1', 'aiu'], ['id1', 'eo']]
>>> l = l * 10000
>>> 
>>> from collections import defaultdict
>>> 
>>> d = defaultdict(str)
>>> with get_time():
	for k,v in l: d[k] += v

	
0.04916644096374512
>>> 
>>> d = defaultdict(list)
>>> with get_time():
	for k,v in l: d[k].append(v)

	
0.011052608489990234
>>> 
>>> from itertools import groupby
>>> with get_time():
	d = [(k, ''.join([item[1] for item in i])) for k,i in groupby(l, key=lambda x:x[0])]

	
0.01807713508605957
>>> 
>>> with get_time():
	d = {id:[i[1] for i in l if i[0]==id] for id in dict(l).keys()}

	
0.005514621734619141
>>> 
>>> 
=============================== RESTART: Shell ===============================
>>> l = [['id0', 'pyt'], ['id0', 'hon'], ['id1', 'aiu'], ['id1', 'eo']]
>>> for k,v in {id:[i[1] for i in l if i[0]==id] for id in dict(l).keys()}.items(): print(k, ''.join(v))

id0 python
id1 aiueo
>>>