make image cleaner comply with PEP8 standards, added comments

bin/image_cleaner.py

@@ -0,0 +1,76 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+"""
+Name: Video2X Image Cleaner
+Author: BrianPetkovsek
+Author: K4YT3X
+Date Created: March 24, 2019
+Last Modified: March 24, 2019
+
+Description: This class is to remove the extracted frames
+that have already been upscaled.
+"""
+
+import os
+import threading
+import time
+
+
+class ImageCleaner(threading.Thread):
+    """ Video2X Image Cleaner
+
+    This class creates an object that keeps track of extracted
+    frames that has already been upscaled and are not needed
+    anymore. It then deletes them to save disk space.
+
+    Extends:
+        threading.Thread
+    """
+
+    def __init__(self, input_folder, output_folder, num_threads):
+        threading.Thread.__init__(self)
+        self.input_folder = input_folder
+        self.output_folder = output_folder
+        self.num_threads = num_threads
+        self.running = False
+
+    def run(self):
+        """ Run image cleaner
+        """
+        self.running = True
+
+        while self.running:
+            self.remove_upscaled_frames()
+            time.sleep(1)
+
+    def stop(self):
+        """ Stop the image cleaner
+        """
+        self.running = False
+        self.join()
+
+    def remove_upscaled_frames(self):
+        """ remove frames that have already been upscaled
+
+        This method compares the files in the extracted frames
+        folder with the upscaled frames folder, and removes
+        the frames that has already been upscaled.
+        """
+
+        # list all images in the extracted frames
+        output_frames = [f for f in os.listdir(self.output_folder) if os.path.isfile(os.path.join(self.output_folder, f))]
+
+        # compare and remove frames downscaled images that finished being upscaled
+        # within each thread's  extracted frames folder
+        for i in range(self.num_threads):
+            dir_path = os.path.join(self.input_folder, str(i))
+
+            # for each file within all the folders
+            for f in os.listdir(dir_path):
+                file_path = os.path.join(dir_path, f)
+
+                # if file also exists in the output folder, then the file
+                # has already been processed, thus not needed anymore
+                if os.path.isfile(file_path) and f in output_frames:
+                    os.remove(file_path)
+                    output_frames.remove(f)