Thread won't run in background?

Question

When I call the my_batch.run_jobs(), my thread does not run in my background. Instead, it runs synchronously by waiting during the method to finish running.

For context, I am calling this method from within a .py file, and the method is within the class. When I run my same function outside of the file/class, it runs in my background just fine.

# package_name/module_name.py

class BaseModel(Model):

    class Meta:

        database = get_db()

class Batch(BaseModel):

    def run_jobs():

        

        def sleeper():

            sleep(999)

        

        t = threading.Thread(target=sleeper)

        #t.daemon = True #tried with/ without

        t.start()

for example

my_batch = Batch()

my_batch.run_jobs()

#doesn't print until line above finishes

print("in progress")

Answer 1

I updated your code for testing. It seems to run as expected.

import time, threading

class BaseModel(): pass

#    class Meta:

#        database = get_db()

class Batch(BaseModel):

    def run_jobs(self):

        

        def sleeper(): # runs in background thread

            for t in range(10):

               print('<sleeper>', t)

               time.sleep(.9)

        

        t = threading.Thread(target=sleeper)

        t.start()

        

        # this runs same time as background thread (sleeper)

        for t in range(10):

           print('<rj>', t)

           time.sleep(.8)

        

mybatch = Batch()

mybatch.run_jobs()  # runs in main thread

# this loop runs after run_jobs completes

for t in range(5):

   print('<main>', t)

   time.sleep(1)

Output

<sleeper> 0

<rj> 0

<rj> 1

<sleeper> 1

<rj> 2

<sleeper> 2

<rj> 3

<sleeper> 3

<rj> 4

<sleeper> 4

<rj> 5

<sleeper> 5

<rj> 6

<sleeper> 6

<rj> 7

<sleeper> 7

<rj> 8

<rj> 9

<sleeper> 8

<main> 0

<sleeper> 9

<main> 1

<main> 2

<main> 3

<main> 4

--- Update ---

Here is the same code split into modules:

-- mike.py

import time, threading

class BaseModel(): pass

#    class Meta:

#        database = get_db()

class Batch(BaseModel):

    def run_jobs(self):

        

        def sleeper(): # runs in background thread

            for t in range(10):

               print('<sleeper>', t)

               time.sleep(.9)

        

        t = threading.Thread(target=sleeper)

        t.start()

        

        # this runs same time as background thread (sleeper)

        for t in range(10):

           print('<rj>', t)

           time.sleep(.8)

-- threadchk.py (main script)

import mike

import time, threading

    

mybatch = mike.Batch()

mybatch.run_jobs()  # runs in main thread

# this loop runs after method completes

for t in range(5):

   print('<main>', t)

   time.sleep(1)

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