import time
from concurrent.futures import ThreadPoolExecutor

# 可回调的task
def pub_task(msg):
  time.sleep(3)
  return msg

# 创建一个线程池
pool = ThreadPoolExecutor(max_workers=3)

# 往线程池加入2个task
task1 = pool.submit(pub_task, 'a')
task2 = pool.submit(pub_task, 'b')

print(task1.done())    # False
time.sleep(4)
print(task2.done())    # True

print(task1.result())
print(task2.result())

from concurrent.futures import ThreadPoolExecutor
import requests

URLS = ['http://www.csdn.com', 'http://qq.com', 'http://www.leasonlove.cn']

def task(url, timeout=10):
  return requests.get(url, timeout=timeout)

pool = ThreadPoolExecutor(max_workers=3)
results = pool.map(task, URLS)

for ret in results:
  print('%s, %s' % (ret.url, ret))

from concurrent.futures import ThreadPoolExecutor
from concurrent.futures import as_completed
import requests

URLS = ['http://www.csdn.cn', 'http://qq.com', 'http://www.leasonlove.cn']

def task(url, timeout=1):
  return requests.get(url, timeout=timeout)

with ThreadPoolExecutor(max_workers=3) as executor:
  future_tasks = [executor.submit(task, url) for url in URLS]

  for f in future_tasks:
    if f.running():
      print('%s is running' % str(f))

  for f in as_completed(future_tasks):
    try:
      ret = f.done()
      if ret:
        f_ret = f.result()
        print('%s, done, result: %s, %s' % (str(f), f_ret.url, f_ret.content))
    except Exception as e:
      # 第一个url无响应
      f.cancel()
      print(str(e))

import asyncio
import time
start = time.time()

async def do(x):
  print('Waiting: ', x)
  await asyncio.sleep(x)
  return 'Finish after {}s'.format(x)

task1 = do(1)
task2 = do(2)
task3 = do(4)

tasks = [
  asyncio.ensure_future(task1),
  asyncio.ensure_future(task2),
  asyncio.ensure_future(task3)
]

loop = asyncio.get_event_loop()
loop.run_until_complete(asyncio.wait(tasks))

for task in tasks:
  print('Task result: ', task.result())

end = time.time()
print('TIME: ', end - start)

# A Simple Python program to demonstrate working 
# of yield 
 
# A generator function that yields 1 for first time, 
# 2 second time and 3 third time 
def simpleGeneratorFun(): 
  yield 1
  yield 2
  yield 3
 
# Driver code to check above generator function 
for value in simpleGeneratorFun(): 
  print(value) 

# A Python program to generate squares from 1 
# to 100 using yield and therefore generator 
 
# An infinite generator function that prints 
# next square number. It starts with 1 
def nextSquare(): 
  i = 1; 
 
  # An Infinite loop to generate squares 
  while True: 
    yield i*i         
    i += 1 # Next execution resumes 
        # from this point   
 
# Driver code to test above generator 
# function 
for num in nextSquare(): 
  if num > 100: 
     break  
  print(num)