This is a working version without significant leak.

import photos
import time
import concurrent.futures
import objc_util
import ui

@objc_util.on_main_thread
def update(image_view, ui_image):
    image_view.image = ui_image

def loop_photos():
    all_photos = photos.get_assets()
    while True:
        for p in all_photos:
            with objc_util.autoreleasepool():
                ui_image = p.get_ui_image(size=(300,300))
                #image_data = p.get_image_data()
                update(v['img'], ui_image)
            time.sleep(.5)
        time.sleep(5)

v = ui.View()
v.add_subview(ui.ImageView(name='img'))
v.present()

with concurrent.futures.ThreadPoolExecutor(max_workers=1) as executor:
    executor.submit(loop_photos)

Thanks very much for all the suggestions. I'm grateful for the tip about threading and will try to incorporate it into the rest of the project but the thing that does the lifting here is the autoreleasepool context manager; with just this addition and removing the threading it works just fine.

@JonB said:

Another few things to try:.

Thanks very much. That link looks like what I've been trying to wrestle together in objc without success. I'll try to implement some of these suggestions and report back.

@JonB

@mrjk have you tried the same code, but without the imageview? I.e just creating the ui.Image's?

Thanks. I hadn't but it does suffer from the same issue.

import photos
import time
all_photos = photos.get_assets()
while True:
    for p in all_photos:
        image = p.get_ui_image(size=(300,300))
        time.sleep(.5)
    time.sleep(5)

@cvp said:

@mrjk said:

I’ve tried setting image to None

That is only if you don't recreate the ImageView in the loop, thus no remove subview

Yes exactly. But I did also try doing it in addition to removing the subview.

@cvp

In the left panel in Xcode which usually shows the project navigation / directory structure there’s a row of icons along the top. Click the 7th one across : “Debug navigator”.

If you select the “memory” from the list it shows charts in the main panel.

Yes, the use of all in my example was very sloppy. I don’t know what came over me.

Thanks for all your suggestions.

I’ve tried setting image to None and deleting the looping variable p but the increasing memory consumption continues.

I was trying to avoid using the objc because I am much more comfortable in Python but I’ll look into it this evening.

Hi all

I've written a script which loops through a list of photos, displaying the current one while some processing happens behind the scenes. I've wrapped this up into an app in Xcode using the Pythonista3AppTemplate and have noticed that the memory consumption grows every time the photo changes. Minimum code to reproduce:

# Code 1
import photos
import ui
import time

v = ui.View()
v.add_subview(ui.ImageView(name = 'img'))
v.present()

all = photos.get_assets()

while True:
    for p in all:
        v['img'].image = p.get_ui_image(size=(300,300))
        time.sleep(.5)
    time.sleep(5)

Xcode shows memory usage steps up every time get_ui_image() is called. The rate of increase is linked to the size argument.

I tried a few things to narrow down where the issue is. This one still loops and changes the image forever but it gets all the ui_images once at the start.

# Code 2
import photos
import ui
import time

v = ui.View()
img = ui.ImageView(name='img')
v.add_subview(img)
v.present()

all = photos.get_assets()[0:5]
images = [p.get_ui_image(size=(300,300)) for p in all]

while True:
    for i in images:
        v['img'].image = i
        time.sleep(.5)
    time.sleep(2)

The memory usage jumps up at the beginning, as you'd expect, but then it stays constant while it loops. This is ok for a small number of photos but impractical if you want to look at the whole photo roll.

I changed the original code so it removes the ImageView entirely to try to get some garbage collection.

import photos
import ui
import time

v = ui.View()
v.present()
all = photos.get_assets()

while True:
    for p in all:
        for sv in v.subviews:
            v.remove_subview(sv)
        img = ui.ImageView(name = 'img')
        img.image = p.get_ui_image(size=(300,300))
        v.add_subview(img)
        time.sleep(.5)
    time.sleep(5)

The memory usage still grows with every change.

I think this shows it's caused by calling get_ui_image(). But is there anything I should (or could) be doing to kick start any garbage collection here? Is this a memory leak in the Pythonista photos module? And can I mitigate it?

Grateful for any advice. J