A simple tool to merge two .bib files when one file only contains books and the other file only contains articles

flatten_bibs.py

import os
import argparse

import bibtexparser


def read_bibtex(fn):
    """Load bib file
    """
    with open(fn) as bibf:
        db = bibtexparser.load(bibf)
    return db


def dump_bibtex(bibtexdb, fn):
    """Save bib file
    """
    with open(fn, 'w') as bibf:
        bibtexparser.dump(bibtexdb, bibf)


def flatten(bib_articles, bib_books, move_books=True,
            to_copy=['title', 'year', 'month', 'location', 'publisher']):
    """Flatten article bib and book bib to one complete bib file
    """
    # init empty DB
    bib_out = bibtexparser.bibdatabase.BibDatabase()

    # copy artices entries
    bib_out.entries = bib_articles.entries

    # flatten out xrefs
    for article in bib_out.entries:
        if 'crossref' in article:
            book = bib_books.entries_dict[article['crossref']]
            for key in to_copy:
                if key in book:
                    article[('booktitle' if key == 'title' else key)] = book[key]

            del article['crossref']

    # move books
    for book in bib_books.entries:
        if book['ENTRYTYPE'] == 'book':
            bib_out.entries.append(book)

    return bib_out


def main(bib_articles_fn, bib_books_fn, out_fn):
    """Main process
    """
    bib_articles = read_bibtex(bib_articles_fn)
    bib_books = read_bibtex(bib_books_fn)
    result = flatten(bib_articles, bib_books)
    dump_bibtex(result, out_fn)


if __name__ == "__main__":
    parser = argparse.ArgumentParser()
    parser.add_argument("articles_bib", type=str, help='path to articles db (.bib)')
    parser.add_argument("books_bib", type=str, help='path to books db (.bib)')
    parser.add_argument("out_fn", type=str, default=os.path.join(os.getcwd(), 'out.bib'),
                        help="path to save flattened output (.bib)")
    args = parser.parse_args()
    
    main(args.articles_bib, args.books_bib, args.out_fn)