这是最简单的方法!
你可以使用asyncio。(文档可以在这里找到)。它被用作多个Python异步框架的基础,这些框架提供了高性能的网络和web服务器、数据库连接库、分布式任务队列等。此外,它有高级和低级api来适应任何类型的问题。
import asyncio
def background(f):
def wrapped(*args, **kwargs):
return asyncio.get_event_loop().run_in_executor(None, f, *args, **kwargs)
return wrapped
@background
def your_function(argument):
#code
现在这个函数将在调用时并行运行,而不会将主程序置于等待状态。你也可以用它来并行for循环。当调用for循环时,虽然循环是顺序的,但每次迭代都是在解释器到达主程序时并行运行的。
1. 发射环平行于主线程没有任何等待
@background
def your_function(argument):
time.sleep(5)
print('function finished for '+str(argument))
for i in range(10):
your_function(i)
print('loop finished')
这将产生以下输出:
loop finished
function finished for 4
function finished for 8
function finished for 0
function finished for 3
function finished for 6
function finished for 2
function finished for 5
function finished for 7
function finished for 9
function finished for 1
更新:2022年5月
虽然这回答了最初的问题,但有一些方法可以让我们按照被点赞的评论的要求等待循环完成。把它们也加在这里。实现的关键是:asyncio.gather() & run_until_complete()。考虑以下函数:
import asyncio
import time
def background(f):
def wrapped(*args, **kwargs):
return asyncio.get_event_loop().run_in_executor(None, f, *args, **kwargs)
return wrapped
@background
def your_function(argument, other_argument): # Added another argument
time.sleep(5)
print(f"function finished for {argument=} and {other_argument=}")
def code_to_run_before():
print('This runs Before Loop!')
def code_to_run_after():
print('This runs After Loop!')
2. 平行跑,但要等待结束
code_to_run_before() # Anything you want to run before, run here!
loop = asyncio.get_event_loop() # Have a new event loop
looper = asyncio.gather(*[your_function(i, 1) for i in range(1, 5)]) # Run the loop
results = loop.run_until_complete(looper) # Wait until finish
code_to_run_after() # Anything you want to run after, run here!
这将产生以下输出:
This runs Before Loop!
function finished for argument=2 and other_argument=1
function finished for argument=3 and other_argument=1
function finished for argument=1 and other_argument=1
function finished for argument=4 and other_argument=1
This runs After Loop!
3.并行运行多个循环并等待完成
code_to_run_before() # Anything you want to run before, run here!
loop = asyncio.get_event_loop() # Have a new event loop
group1 = asyncio.gather(*[your_function(i, 1) for i in range(1, 2)]) # Run all the loops you want
group2 = asyncio.gather(*[your_function(i, 2) for i in range(3, 5)]) # Run all the loops you want
group3 = asyncio.gather(*[your_function(i, 3) for i in range(6, 9)]) # Run all the loops you want
all_groups = asyncio.gather(group1, group2, group3) # Gather them all
results = loop.run_until_complete(all_groups) # Wait until finish
code_to_run_after() # Anything you want to run after, run here!
这将产生以下输出:
This runs Before Loop!
function finished for argument=3 and other_argument=2
function finished for argument=1 and other_argument=1
function finished for argument=6 and other_argument=3
function finished for argument=4 and other_argument=2
function finished for argument=7 and other_argument=3
function finished for argument=8 and other_argument=3
This runs After Loop!
4. 循环按顺序运行,但每个循环的迭代都是彼此并行运行的
code_to_run_before() # Anything you want to run before, run here!
for loop_number in range(3):
loop = asyncio.get_event_loop() # Have a new event loop
looper = asyncio.gather(*[your_function(i, loop_number) for i in range(1, 5)]) # Run the loop
results = loop.run_until_complete(looper) # Wait until finish
print(f"finished for {loop_number=}")
code_to_run_after() # Anything you want to run after, run here!
这将产生以下输出:
This runs Before Loop!
function finished for argument=3 and other_argument=0
function finished for argument=4 and other_argument=0
function finished for argument=1 and other_argument=0
function finished for argument=2 and other_argument=0
finished for loop_number=0
function finished for argument=4 and other_argument=1
function finished for argument=3 and other_argument=1
function finished for argument=2 and other_argument=1
function finished for argument=1 and other_argument=1
finished for loop_number=1
function finished for argument=1 and other_argument=2
function finished for argument=4 and other_argument=2
function finished for argument=3 and other_argument=2
function finished for argument=2 and other_argument=2
finished for loop_number=2
This runs After Loop!
更新:2022年6月
这在目前的形式可能无法运行在某些版本的jupyter笔记本电脑。原因是jupyter笔记本利用事件循环。要使它在这样的jupyter版本上工作,nest_asyncio(从名称可以看出,它将嵌套事件循环)是可行的方法。只需导入并应用它在单元格的顶部:
import nest_asyncio
nest_asyncio.apply()
上面讨论的所有功能在笔记本环境中也应该可以访问。