Here's a baby example - searching in a nested loop. Suppose we're looking for the word 'apple' in a collection of books. Once we've found it, we stop.

    for book in books:
        for page in book:
            if 'apple' in page:
                break
        if break:
            break

However, suppose we say that we only look at the first 5000 or so words in each book. (We suppose a page is a list of words.)

This leads to the following code.

    for book in books:
        word_count = 0
        for page in book:
            word_count += len(page)
            if word in page:
                break
            if word_count >= 5000:
                break found
        if break found:
            break

At this time, I'd like us to focus on examples of existing code, and semantics that might be helpful. I think once we have this, the discussion of syntax will be easier.

By the way, the word_count example is as I typed it, but it has a typo. Did you spot it when you read it? (I only noticed it when re-reading my message.)

Finally, thank you for your contributions. More examples please.

-- 

Jonathan