import time
from concurrent.futures import ThreadPoolExecutor

def test(name):
print "write to db " + name

name_list = ['Lucy', 'Lily', 'Tom', 'Lucy2', 'Lily2', 'Tom2', 'Lucy3', 'Lily3', 'Tom3']

#start = time.time()
#for i in range(9):
#test(name_list[i])
#end = time.time()
#print end - start # 7.00950622559e-05

pool = ThreadPoolExecutor(max_workers=3)
start = time.time()
for i in range(9):
test(name_list[i])
pool.submit(test, name_list[i])
pool.shutdown(wait=True) # pool.shutdown(wait=True)是进程池内部的进程都执行完毕，才会关闭，然后执行后续代码
end = time.time()
print end - start # 0.0054759979248