Better way to append frames from a video to multiple lists?

[Balaganesh]

Hi, I am trying to split a video based on the index and value stored in a text file. The index represents the frame number and value represents frame class. Then I create multiples lists based on the count of unique values in the text file and split the videos and append the frames to a list based on the frame number. But this operation on a larger video crashes my python because of memory issues. Is there a better way to do this? Here is an example text https://pastebin.com/Shdw2C0d

In the code, I am referring to line 28. Thanks for your time.

import numpy as np
import cv2
import os
from collections import defaultdict

# Create a generator to let you loop over the video in a for loop
def get_frames(vid):
    while True:
        ret, frame = vid.read()
        if not ret:
            return
        yield frame


def split_videos(txt_file, video_file):

    with open(txt_file,'r') as f:
        frame_numbers = list(map(int, f.read().split()))
        size = len(set(frame_numbers))

    offset = min(frame_numbers)
    frame_groups = [[] for _ in range(7)]

    video = cv2.VideoCapture(video_file)
    

    for index, frame in zip(frame_numbers, get_frames(video)):
        frame_groups[index - offset].append(frame)

    video.release()

    frame_groups_final = [x for x in frame_groups if x]
    codec = cv2.VideoWriter_fourcc(*'XVID')

    for index, group in enumerate(frame_groups_final):
    # Arguments are filename, codec, framerate, resolution
        print((len(group[0]), len(group[0][0])))
        writer = cv2.VideoWriter(f'video_{index + offset}.avi', codec, 30.0, (len(group[0][0]), len(group[0])))
        for frame in group:
            writer.write(frame)
        writer.release()
    cv2.destroyAllWindows()