CODEWITHSUNDEEP
python
Abhinav
Abhinav

Reputation: 195

Execute a part of that function only once, but the function itself multiple times. Python

I know the question seems very weird, but maybe this example can lay it out more clearly.

def entry_point():
  if list_already_exists:
     list.append(something)
  else:
     list = [something]
  run_program(list)

def run_program(list):
  for idx, value in enumerate(list):
     print(idx)
     time.sleep(value)

So run_program is the actual function which does everything(kind of like the driver code) entry_point can be called many times even when run_program is under execution.

With the current approach, whenever I try to modify the list, run_program starts all over again from the beginning.

I don't want that. I want entry_point to execute run_program just once and next time I run entry_point to modify list, run_program shouldn't be interrupted, only the updated list should be passed to run_program.

Intended output

first ever call to entry_point() should create a new list, lets assume list = [1]

entry_point() --> run_program(list) output would be 1 and wait for 1 sec

second call to entry_point() adds something to the already existing list. list = [1,2]

meanwhile, after one second wait, run_program(list) would print 2 and wait for 2 secs

So on and so forth...

Any help would be much appreciated..

Upvotes: 0

Views: 320

Answers (2)

Altaf Shaikh
Altaf Shaikh

Reputation: 282

I agree with others that the behavior you described is more suited to listers, event emitters or threads. However, I am still unsure of the exact use case you need it for. Following is a simple implementation without any of the mentioned things - that satisfies the flow you mentioned. You can tweak it according to the need if it fits your constraints.

All calls to the entry_point also pass a index to the run_program function and hence the global list is updated and each time the correct value is chosen for the sleep function. Hope it helps to some extent.

import time

global val
val = 1
global lst

def entry_point():
    global val
    global lst
    try:
        lst.append(val)
    
    except:

        lst = [val]
 
    idx = lst.index(val)
    run_program(lst, idx)

    val += 1



def run_program(lst, idx):
    value = lst[idx]
    print(f'Index is {idx} and value is {value}')
    time.sleep(value)


entry_point()
entry_point()

Upvotes: 1

itogaston
itogaston

Reputation: 399

To me it sounds like you need some kind of Thread to keep run_program executing while you modify the list in the entry_point function.

You can pass the list in a Queue and make the run_program function continue in the point it left the previous list.

Upvotes: 0

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