Python 调度程序未运行导入中调度的函数

Question

问题

当这段代码:

# main.py - this file gets run directly.
import sched
import time
scheduler = sched.scheduler(time.time, time.sleep)

print("before definition")

def do_something():
    print("do_something is being executed.")
    scheduler.enter(1, 5, do_something)

print("post definition")
scheduler.enter(1, 5, do_something)

# Do something, so that the program does not terminate.
do_not_terminate()

位于被调用的文件(main.py)中，它按预期运行(每秒运行 do_something 函数。)，产生以下输出:

before definition
post definition
do_something is being executed.
do_something is being executed.
do_something is being executed.
do_something is being executed.
do_something is being executed.
do_something is being executed.
...

但是:

当上面的 block 被放入一个单独的文件(someimport.py)并且someimport.py被导入到main.py中时do_something 函数不再被执行。 [代码如下所示:]

# someimport.py - this file gets imported in main.py
import sched
import time
scheduler = sched.scheduler(time.time, time.sleep)

print("before definition")

def do_something():
    print("do_something is being executed.")
    scheduler.enter(1, 5, do_something)

print("post definition")
scheduler.enter(1, 5, do_something)

# main.py - this file get's run directly
import someimport

# Do something, so that the program does not terminate.
do_not_terminate()

仅产生以下输出(当然不会出现错误消息):

before definition
post definition

我已经尝试过以下操作:

1. 将 main.py 中的 import someimport 切换为 from someimport import *

正如预期的那样，这并没有改变任何东西。

2. 将第一个 scheduler.enter 调用放入一个单独的函数( run)中，该函数在导入后调用:

# someimport.py - this file gets imported in main.py
import sched
import time
scheduler = sched.scheduler(time.time, time.sleep)

print("before definition")

def do_something():
    print("do_something is being executed.")
    scheduler.enter(1, 5, do_something)

print("post definition")
def run():
    scheduler.enter(1, 5, do_something)

# main.py - this file get's run directly
import someimport

someimport.run()

# Do something, so that the program does not terminate.
do_not_terminate()

这并没有改变任何东西。

3. 在 main.py中导入 sched和 time。

正如预期的那样，这也没有任何效果。

有没有办法在 someimport.py 中安排 do_something 函数，而无需在 main.py 文件中使用第一个 scheduler.enter 。这就是我试图避免的事情(因为在实际项目中大约有 100 个这样的计划任务，我正在尝试清理主文件)。

以上所有代码均已在 GNU/Linux 下的 python 3.7.3 上进行了测试。

非常感谢!

Answer 1

将单独的模块示例导入 main.py 后，我只需在 scheduler 实例上调用 run() 即可让其正常工作。

# main.py - this file get's run directly
import someimport

someimport.scheduler.run()  # Blocks until all events finished

产品:

before definition
post definition
do_something is being executed.
do_something is being executed.

根据the docs ，必须调用 scheduler.run() 才能运行任何计划任务。 scheduler.enter() 方法本身只会安排事件，而不是运行它们。