Added get_random_best code. Added the AB test

pytest.ini

@@ -1,8 +1,11 @@
 [pytest]
 env =
-    DATABASE_URL=postgresql+asyncpg://app:app@app_db/postgres
     SITE_URL=
+    DATABASE_URL=postgresql+asyncpg://app:app@app_db:5432/app
     REDIS_URL=redis://:myStrongPassword@redis:6379
+    # no docker version, useful for debugging
+    # DATABASE_URL=postgresql+asyncpg://app:[email protected]:65432/app
+    # REDIS_URL=redis://:[email protected]:36379
 
     SITE_DOMAIN=127.0.0.1
     SECURE_COOKIES=false

src/recommendations/candidates.py

@@ -399,3 +399,84 @@ async def get_best_memes_from_each_source(
     """
     res = await fetch_all(text(query))
     return res
+
+
+async def get_random_best(
+    user_id: int,
+    limit: int = 10,
+    exclude_meme_ids: list[int] = [],
+):
+    """Selects 'limit' best memes from the top 100 memes obtained using the cleared
+    meme statistics. The cleared statistics aggregates reactions from users with
+    less than 200 previous reactions. It's aim is to remove the bias from old users
+    """
+
+    query = f"""
+        SELECT
+            M.id
+            , M.type, M.telegram_file_id, M.caption, M.recommended_by
+        FROM (
+            SELECT
+                M.id
+                , M.type, M.telegram_file_id, M.caption
+                , 'random_best_ab_240422' AS recommended_by
+                , random() rand
+            FROM meme M
+            INNER JOIN meme_stats MS
+                ON MS.meme_id = M.id
+
+            INNER JOIN user_language L
+                ON L.user_id = {user_id}
+                AND L.language_code = M.language_code
+
+            LEFT JOIN user_meme_reaction R
+                    ON R.meme_id = M.id
+                    AND R.user_id = {user_id}
+
+            WHERE 1=1
+                AND M.status = 'ok'
+                AND R.meme_id IS NULL
+                -- 100 ru, 50 en, 50 all lang
+                AND M.id IN (
+                    4101086, 4442353, 3755262, 4524041, 914304, 1213657,
+                    3477742, 3850309, 4106545, 3918656, 1976055, 3729527,
+                    4370768, 4031941, 3902467, 3940729, 3966109, 4144377,
+                    4131644, 4720051, 4438220, 943398, 3486879, 3958437,
+                    3193252, 4011185, 3855063, 4261258, 4368086, 4255270,
+                    1194244, 10222, 4818828, 3820043, 758408, 3188657,
+                    4451345, 2050874, 4665040, 4106819, 3798967, 1825631,
+                    3140601, 4840661, 4250457, 10202, 4363045, 3823857,
+                    3755199, 4214428, 3604880, 3759401, 3928967, 3859587,
+                    1240438, 4634391, 4002944, 2914449, 1955395, 1902244,
+                    4256739, 1721327, 1285555, 1901653, 1584871, 3517077,
+                    4493086, 4128512, 3570595, 3975285, 1484762, 1811655,
+                    1071204, 4033401, 2294710, 4236782, 881987, 4180263,
+                    1100991, 3867070, 1859048, 4285721, 1466518, 2262302,
+                    4478289, 1859157, 4232654, 1202886, 978202, 2279188,
+                    1892350, 961273, 4033397, 3513207, 3635346, 4320621,
+                    4558947, 4252321, 1084225, 2350587, 4339982, 3724969,
+                    3613758, 1768655, 4148626, 1285566, 2181541, 1103300,
+                    3516406, 1197518, 4036174, 3537906, 2953444, 13636,
+                    3724910, 3911502, 1988648, 3587199, 1398183, 4166913,
+                    3911320, 1311422, 2153377, 3604881, 3596142, 1006843,
+                    4473556, 4231678, 4856209, 10114, 3520485, 4232460,
+                    1721545, 3747694, 3914292, 4119263, 4033399, 1482707,
+                    4243473, 4336344, 1678337, 3516170, 2279191, 3724979,
+                    3772372, 4763033, 4128276, 463991, 1006837, 1202853,
+                    4101086, 1103300, 4119263, 4357615, 1194244, 3859587,
+                    3630862, 4478289, 4665040, 3798967, 3940785, 10222,
+                    4255187, 1304918, 3823857, 1398183, 16818, 881987,
+                    2005796, 3639651, 4231648, 3902342, 4031503, 4231678,
+                    4166913, 4720051, 3855063, 4370768, 2350587, 758408,
+                    4818828, 4261258, 3587199, 648225, 4716664, 3918656,
+                    4183519, 3600534, 4473556, 3772372, 4243473, 4524041,
+                    943398, 4840661, 4250457, 1825631, 4363045, 4232460,
+                    4148761, 3513207
+                )
+                {exclude_meme_ids_sql_filter(exclude_meme_ids)}
+            ORDER BY rand
+            LIMIT {limit}
+        ) M
+    """
+    res = await fetch_all(text(query))
+    return res

src/recommendations/meme_queue.py

@@ -4,6 +4,7 @@
 from src.recommendations.candidates import (
     classic,
     get_best_memes_from_each_source,
+    get_random_best,
     less_seen_meme_and_source,
     like_spread_and_recent_memes,
 )
@@ -45,9 +46,19 @@ async def generate_cold_start_recommendations(user_id, limit=10):
     memes_in_queue = await redis.get_all_memes_in_queue_by_key(queue_key)
     meme_ids_in_queue = [meme["id"] for meme in memes_in_queue]
 
-    candidates = await get_best_memes_from_each_source(
-        user_id, limit=limit, exclude_meme_ids=meme_ids_in_queue
-    )
+    candidates = []
+
+    # AB test
+    if user_id % 100 < 50:
+        candidates = await get_random_best(
+            user_id, limit=limit, exclude_meme_ids=meme_ids_in_queue
+        )
+
+    if len(candidates) == 0:
+        candidates = await get_best_memes_from_each_source(
+            user_id, limit=limit, exclude_meme_ids=meme_ids_in_queue
+        )
+
     if len(candidates) == 0:
         return
 
@@ -63,10 +74,18 @@ async def generate_recommendations(user_id, limit):
 
     r = random.random()
 
+    candidates = []
+
     if user_info["nmemes_sent"] < 30:
-        candidates = await get_best_memes_from_each_source(
-            user_id, limit=limit, exclude_meme_ids=meme_ids_in_queue
-        )
+        # AB test
+        if user_id % 100 < 50:
+            candidates = await get_random_best(
+                user_id, limit=limit, exclude_meme_ids=meme_ids_in_queue
+            )
+        if len(candidates) == 0:
+            candidates = await get_best_memes_from_each_source(
+                user_id, limit=limit, exclude_meme_ids=meme_ids_in_queue
+            )
 
     elif user_info["nmemes_sent"] < 100:
         if r < 0.5:

src/tgbot/app.py

@@ -57,7 +57,6 @@
 from src.tgbot.handlers.moderator import get_meme, meme_source
 from src.tgbot.handlers.stats.stats import handle_stats
 from src.tgbot.handlers.stats.wrapped import handle_wrapped, handle_wrapped_button
-
 from src.tgbot.handlers.upload import upload_meme
 
 application: Application = None  # type: ignore

tests/recommendations/test_random_best.py

@@ -0,0 +1,100 @@
+from datetime import datetime
+
+import pytest
+import pytest_asyncio
+from sqlalchemy import delete, insert, select
+from sqlalchemy.ext.asyncio import AsyncConnection
+
+from src import redis
+from src.database import (engine, meme, meme_source, meme_stats, user,
+                          user_language, user_meme_reaction)
+from src.recommendations.candidates import get_random_best
+from src.recommendations.meme_queue import generate_cold_start_recommendations
+
+
+@pytest_asyncio.fixture()
+async def conn():
+    async with engine.connect() as conn:
+
+        await conn.execute(
+            insert(user),
+            [{'id': 1, 'type': "user"}, {'id': 51, 'type': "user"}]
+        )
+        await conn.execute(
+            insert(meme_source),
+            {'id': 1, 'type': 'telegram', 'url': '111', 'status': 'parsing_enabled', 'created_at': datetime(2024, 1, 1)}
+        )
+        meme_basic = {
+            'raw_meme_id': 1, 'type': 'image', 'telegram_image_id': '111', 'caption': '111', 'meme_source_id': 1,
+            'published_at': datetime(2024, 1, 1), 'status': 'ok', 'language_code': 'ru',
+        }
+        good_meme_1 = 4101086
+        good_meme_2 = 4442353
+        seen_meme = 3755262
+        bad_meme = 1
+        meme_ids = [good_meme_1, good_meme_2, seen_meme, bad_meme]
+
+        await conn.execute(
+            insert(meme),
+            [meme_basic.copy() | {'id': meme_id, 'raw_meme_id': meme_id} for meme_id in meme_ids]
+        )
+        await conn.execute(
+            insert(meme_stats),
+        [{'meme_id': meme_id} for meme_id in meme_ids],
+        )
+        await conn.execute(
+            insert(user_language),
+            [
+                {'user_id': 1, 'language_code': 'ru', 'created_at': datetime(2024, 1, 1)},
+                {'user_id': 51, 'language_code': 'ru', 'created_at': datetime(2024, 1, 1)}
+            ]
+        )
+        await conn.execute(
+            insert(user_meme_reaction),
+            [
+                {'user_id': 1, 'meme_id': seen_meme, 'reaction_id': 1, 'recommended_by': '111', 'sent_at': datetime(2024, 1, 1)},
+                {'user_id': 51, 'meme_id': seen_meme, 'reaction_id': 1, 'recommended_by': '111', 'sent_at': datetime(2024, 1, 1)}
+            ]
+        )
+
+        await conn.commit()
+        yield conn
+
+        await conn.execute(delete(user_meme_reaction))
+        await conn.execute(delete(user_language))
+        await conn.execute(delete(meme_stats))
+        await conn.execute(delete(meme))
+        await conn.execute(delete(meme_source))
+        await conn.execute(delete(user))
+        await conn.commit()
+
+        queue_key = redis.get_meme_queue_key(1)
+        await redis.delete_by_key(queue_key)
+        queue_key = redis.get_meme_queue_key(51)
+        await redis.delete_by_key(queue_key)
+
+        # TODO: redis sends the runtime error after the test succeeds
+        # RuntimeError: Event loop is closed
+
+
+@pytest.mark.asyncio
+async def test_random_best(conn: AsyncConnection):
+    recs = await get_random_best(1, 10)
+    assert len(recs) == 2
+
+
+@pytest.mark.asyncio
+async def test_random_best_meme_queue(conn: AsyncConnection):
+    user_id = 1
+    await generate_cold_start_recommendations(user_id)
+    queue_key = redis.get_meme_queue_key(user_id)
+    recs = await redis.get_all_memes_in_queue_by_key(queue_key)
+    assert len(recs) == 2
+    assert recs[0]['recommended_by'] == 'random_best_ab_240422'
+
+    user_id = 51
+    await generate_cold_start_recommendations(user_id)
+    queue_key = redis.get_meme_queue_key(user_id)
+    recs = await redis.get_all_memes_in_queue_by_key(queue_key)
+    assert len(recs) == 1
+    assert recs[0]['recommended_by'] == 'best_meme_from_each_source'