How to sort objects in Python based of a numerical value belonging to the object

Question

I have a python program that can collect information about books from html files. The information includes weight, size, shape author etc. How would I go about writing a piece of code that could "package" x number of books in n boxes with each box having no more than 10lb?

I imagine there are two ways to go about this, one way is to package each box sequentially unitl it was <= 10. The second way is to package the books most effieciently so that there only the fewest number ok boxes was required.

Here is my algorithm for collecting the information:

import glob
import json
from bs4 import BeautifulSoup

def main():
    data = []
    for filename in glob.iglob('*.html'):
        with open(filename) as f:
            soup = BeautifulSoup(f)

            title = soup.find("span", id="btAsinTitle")
            data.append({
                "title":  title.get_text(),
                "author": title.find_next("a", href=True).get_text(),
                "isbn":   soup.find('b', text='ISBN-10:').next_sibling,
                "weight": soup.find('b', text='Shipping Weight:').next_sibling,
                "price":  soup.find('span', {"class":'bb_price'}).get_text()
            })

    with open("my_output.json", "w") as outf:
        json.dump(data, outf, indent = 1)

main()