How to use async/await in Python
In asynchronous programming, the async and await keywords are used to create and manage coroutines.
Create a coroutine
Defining a coroutine function is just like defining regular functions, except that the definition starts with async def instead of just def.
example:
The await keywords pauses a coroutine, until another coroutine is fully executed.
It has the following syntax:
In asynchronous programming, the async and await keywords are used to create and manage coroutines.
- The async keyword creates coroutine function.
- The await keyword is used inside of a coroutine function to wait for the execution of another coroutine.
Create a coroutine
Defining a coroutine function is just like defining regular functions, except that the definition starts with async def instead of just def.
example:
async def add(a, b): print(f'{a} + {b} = {a + b}')To execute a coroutine, we use the asyncio.run() function.
import asyncio async def add(a, b): print(f'{a} + {b} = {a + b}') #create a coroutine object coro = add(10, 20) #run the coroutine asyncio.run(coro) #executes the code in the coroutine
Output:10 + 20 = 30
Execute a coroutine inside of another coroutineThe await keywords pauses a coroutine, until another coroutine is fully executed.
It has the following syntax:
await coroConsider the following example:
import asyncio #prints even numbers from 0-n async def display_evens(n): for i in range(n): if i % 2 == 0: print(i) async def main(): print("Started!") await display_evens(10) #await display_evens() print('Finished!') #run main asyncio.run(main())
Output:Started!
0
2
4
6
8
Finished!
Larz60+ write Apr-01-2024, 09:07 AM:
clickbait links removed
clickbait links removed