Python: bind method outside loop to reduce overhead

Came across this interesting pattern in some of the sklearn codebase:

        # bind method outside of loop to reduce overhead
        ngrams_append = ngrams.append

        for n in range(min_n, min(max_n + 1, text_len + 1)):
            for i in range(text_len - n + 1):
                ngrams_append(text_document[i: i + n])
        return ngrams

 

I wonder, at what scale does this really start to make a meaningful performance difference?

Even if it doesn’t make a huge difference, I do find it pretty elegant and easy to follow.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.