Question

Having trouble finding a python solution to matching elements of one list against elements in another list without a whole pile of “for” and “if” loops. I’m hoping to find a better way to do this. I have some big iterating loops that go through multiple lists to perform matches. On a match, I want elements of the list removed. Here are two examples:

def score_and_retweet(auth):
    api = tweepy.API(auth)
    for tweet in api.home_timeline(count=100, include_rts=0):
        for goodword in tweet_whitelist:
            if goodword in tweet.text and tweet.retweet_count >= 2:
                try:
                    api.retweet(tweet.id_str)
                except tweepy.error.TweepError:
                    error_id = tweet.id_str

and

t = time.localtime()
    if t.tm_hour is 14 and (t.tm_wday is 1 or t.tm_wday is 4):
        htmlfiles = glob.glob(html_file_dir+'/*.html')
        for file in htmlfiles:
            for badword in filename_badwords:
                if badword in file:
                    try:
                        htmlfiles.remove(file)
                    except ValueError:
                        error = "already removed"

Answer 1

Not sure how much it would change in terms of performance, but you could write a filter function

For example in the second case (if you’re looking for exact matches)

def fileFilter(f):
    if f in filename_badwords:
        return False
    else:
        return True

Then use:

goodFiles = filter(fileFilter, htmlfiles)

The advantage this has over set intersection is you can make the filter function as complex as you want (you have multiple conditions in your first example)