Python: Define function with name from variable string

Question

I'm building a script which has multiple task loops, with different intervals. Naturally I would want to make a for-loop to define all of these, to make it take up less space. However, it seems like it's not possible to do so.

How can I shorten down this snippet? Is there actually a way?

timeloops = ["60","600","3600","7200","14400","21600"]

@tasks.loop(seconds=60)
async def task_60(self):
    await second_func(self,channels["60"])

@tasks.loop(seconds=600)
async def task_600(self):
    await second_func(self,channels["600"])

@tasks.loop(seconds=3600)
async def task_3600(self):
    await second_func(self,channels["3600"])

@tasks.loop(seconds=7200)
async def task_7200(self):
    await second_func(self,channels["7200"])

@tasks.loop(seconds=14400)
async def task_14400(self):
    await second_func(self,channels["14400"])

@tasks.loop(seconds=21600)
async def task_21600(self):
    await second_func(self,channels["21600"])

Another question on here lead me to use Globals, but it seems like that's only for calling the function, and not for defining it.

Thank you in advance.

This may help stackoverflow.com/questions/11553721/….

Kota Mori
– Kota Mori

2021-08-02 00:45:50 +00:00
Commented Aug 2, 2021 at 0:45 — Kota Mori
– Kota Mori, Commented Aug 2, 2021 at 0:45

Samwise · Accepted Answer · 2021-08-02 00:55:41Z

1

I'm not able to test this since you didn't provide an MRE, but I think building them as a list should be doable:

task_loops = [
    tasks.loop(seconds=int(secs))(
        lambda self, secs=secs: (
            await second_func(self.channels[secs]) for _ in '_'
        ).__anext()
    ) for secs in timeloops
]

The part I'm a little fuzzy on is whether you can define an async lambda that way. This should also work:

task_loops = []
for secs in timeloops:
    @tasks.loop(seconds=int(secs))
    async def task_secs(self, secs=secs):
        await second_func(self, channels[secs])
    task_loops.append(task_secs)

answered Aug 2, 2021 at 0:55

Samwise

72.1k3 gold badges36 silver badges52 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Malcolm · Accepted Answer · 2021-08-02 01:11:56Z

1

If you really need them as methods on your class then you may be able to get it working by creating a parameterised version of your tasks method:

async def timed_task(self, t):
    await second_func(self, channels[t])

And then using the functools.partialmethod function to create the individual instances of the method (perhaps put this in the __init__ of the class):

from functools import partialmethod

for t in timeloops:
    # Create the tasks.loop wrapper
    wrapper = tasks.loop(seconds=int(t))
    # Create the method to be wrapped
    wrapped = partialmethod(timed_task, t)
    setattr(self, f"task_{t}", wrapper(wrapped))

answered Aug 2, 2021 at 1:11

Malcolm

3152 silver badges9 bronze badges

Comments

fitz · Accepted Answer · 2021-08-02 01:57:13Z

1

You can use exec to execute function definition and use string formatting to fill variables. You can try the following code.

import inspect

timeloops = ["60", "600", "3600", "7200", "14400", "21600"]

for i in timeloops:
    define_func = f"""
    @tasks.loop(seconds=int(i))
    async def task_{i}(self):
        await second_func(self,channels[f"{i}"])
    """
    define_func = inspect.cleandoc(define_func)
    exec(define_func)

or the simpler way

timeloops = ["60", "600", "3600", "7200", "14400", "21600"]

for i in timeloops:
    @tasks.loop(seconds=int(i))
    async def task(self, i=i):  # Prevent variable i from being overwritten
        await second_func(self,channels[i])

    exec(f'task_{i}=task')

edited Aug 2, 2021 at 1:57

answered Aug 2, 2021 at 1:40

fitz

5904 silver badges18 bronze badges

Collectives™ on Stack Overflow

Python: Define function with name from variable string

3 Answers 3

Comments

Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

Comments

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related