TypeError: create_task () got an unexpected keyword argument 'name'-CodePudding

Run into a problem when using asyncio module, the code is as follows:

 import asyncio 
Async def func () : 
Print (1) 
Await asyncio. Sleep (2) 
Print (2) 
Return "return value" 


Async def main () : 
Print (' main start ') 
Task_list=[
Asyncio. Create_task (func (), name='t1'), 
Asyncio. Create_task (func (), name='t2') 
] 
Print (' main end ') 

Done, pending=await asyncio. Wait (task_list, timeout=None) 
Print (done) 

Asyncio. Run (the main ())

After the task_list, add the name error

Error message is as follows:

 D: work/study documents/crawler//protector/asyncio crawler courseware and task. The py: 12: RuntimeWarning: coroutine 'func' was never awaited 
Asyncio. Create_task (func (), name='t1'), 
RuntimeWarning: Enable tracemalloc to get the object allocation traceback 
Traceback (the most recent call last) : 
The File "D:/work/study documents/crawler/crawler courseware protector/asyncio and task. Py", line 20, in & lt; module> 
Asyncio. Run (the main ()) 
The File "D: \ python3.7.6 \ lib \ asyncio \ runners py", line 43, in the run 
The return loop. Run_until_complete (main) 
The File "D: \ python3.7.6 \ lib \ asyncio \ base_events py", line 583, in run_until_complete 
Return the future. The result () 
The File "D:/work/study documents/crawler/crawler courseware protector/asyncio and task. Py", line 12, in the main 
Asyncio. Create_task (func (), name='t1'), 
TypeError: create_task () got an unexpected keyword argument 'name'

CodePudding user response:

1, we can see the source asyncio. Create_task () :

 def create_task (coro) : 
"" "the Schedule the execution of a coroutine object in a spawn task. 

Return a Task object. 
"" "
Loop=events. Get_running_loop () 
The return loop. Create_task (coro)

2, and found that the parameter, if do not have this name so change code:

 import asyncio 
Async def func () : 
Print (1) 
Await asyncio. Sleep (2) 
Print (2) 
Return "return value" 


Async def main () : 
Print (' main start ') 
Task_list=[
Asyncio. Create_task (func ()) 
# asyncio. Create_task (func ()) 
] 
Print (' main end ') 

Done, pending=await asyncio. Wait (task_list, timeout=None) 
Print (done) 

Asyncio. Run (the main ())

3, the results are as follows:

 main start 
The main end 
1 
2 
{& lt; The Task finished coro=& lt; Func () done, defined the at F:/python_study/main. Py: 2 & gt; Result='return value & gt; }

CodePudding user response:

reference 1st floor NoamaNelson response:

1, we can see the source code asyncio. Create_task () :

 def create_task (coro) : 
"" "the Schedule the execution of a coroutine object in a spawn task. 

Return a Task object. 
"" "
Loop=events. Get_running_loop () 
The return loop. Create_task (coro)

2, and found that the parameter, if do not have this name so change code:

 import asyncio 
Async def func () : 
Print (1) 
Await asyncio. Sleep (2) 
Print (2) 
Return "return value" 


Async def main () : 
Print (' main start ') 
Task_list=[
Asyncio. Create_task (func ()) 
# asyncio. Create_task (func ()) 
] 
Print (' main end ') 

Done, pending=await asyncio. Wait (task_list, timeout=None) 
Print (done) 

Asyncio. Run (the main ())

3, the results are as follows:

 main start 
The main end 
1 
2 
{& lt; The Task finished coro=& lt; Func () done, defined the at F:/python_study/main. Py: 2 & gt; Result='return value & gt; }

Really don't have the name is not an error, but why will add the name error, I was written according to the teacher, the teacher does not have the error, don't know what's wrong