[Testing:Developer] Fix Python linting errors (Submitty#8242)

* Fix errors

* Append strings instead of using multiline comment

bin/grading_done.py

@@ -234,7 +234,7 @@ def __init__(self, json_file, epoch_time, is_grading):
         # the 'GRADING_' file.
         if is_grading:
             base, tail = os.path.split(json_file)
-            assert(tail.startswith('GRADING_'))
+            assert tail.startswith('GRADING_')
 
             with open(json_file, 'r') as infile:
                 self.grading_queue_obj = json.load(infile)

bin/set_allowed_mins.py

@@ -64,8 +64,8 @@ def send_data(db, allowed_minutes, override):
     db.execute(text(query), gradeable=GRADEABLE)
     if override is not None:
         for user in override:
-            query = """INSERT INTO gradeable_allowed_minutes_override (g_id, user_id, allowed_minutes)
-                       VALUES (:gradeable, :userid, :minutes)"""
+            query = "INSERT INTO gradeable_allowed_minutes_override (g_id, user_id, allowed_minutes) " +\
+                    "VALUES (:gradeable, :userid, :minutes)"  # noqa: E501
             db.execute(text(query), gradeable=GRADEABLE, userid=user['user'],
                        minutes=user['allowed_minutes'])
 

sbin/submitty_daemon_jobs/submitty_jobs/submitty_ocr.py

@@ -72,7 +72,7 @@ def preprocess(img):
     contours, _ = cv2.findContours(img_final_bin, cv2.RETR_TREE,
                                    cv2.CHAIN_APPROX_SIMPLE)
 
-    if(len(contours) == 0):
+    if len(contours) == 0:
         return []
 
     contours, boundingBoxes = sort_contours(contours)
@@ -82,7 +82,7 @@ def preprocess(img):
     # get the individual images
     for c in contours:
         x, y, w, h = cv2.boundingRect(c)
-        if(w > 20 and w < 75 and h > 35 and h < 125):
+        if w > 20 and w < 75 and h > 35 and h < 125:
             idx += 1
             new_img = img[y:y+h, x:x+w]
             # convert to MNIST expected img