If you have a list, say of imports, where there is no semantic meaning in the ordering, alphabetize it. Alphabetizing makes it easier to find duplicates. For example Unsorted Find the duplicate: import os import argparse import copy import sys import datetime import selenium.webdriver.support.expected_conditions import datafetcher import passlib.hash import multiprocessing import db import ttest import backtester import numpy import json import serializers import errors import sys import pytest import traceback import time import selenium.webdriver