An event loop runs tasks created from coroutines, executing one task at a time and switching when a task completes or pauses at an await point. asyncio.run() creates and starts the loop, which runs until its managed tasks finish. section 7.5.1
Listing 7.17 asyncio example
import asyncio
import time
async def func1():
print("Start func1")
await asyncio.sleep(5)
print("End func1")
return "func1 complete"
async def func2():
print("Start func2")
await asyncio.sleep(3)
print("End func2")
return "func2 complete"
async def main():
start_time = time.time()
co_routines = asyncio.gather(func1(), func2())
a, b = await co_routines
print(a, b)
end_time = time.time()
print("time", end_time-start_time)
asyncio.run(main())
Two coroutines pause for different durations; asyncio.gather() lets the event loop run them concurrently and collect their results. section 7.5.1
