BibTex Field Purify

purify.py

# -*- coding: utf-8 -*-
#
# BibTeX Purify
#
# Description
#   This script will purify the BibTex file's fields and *overwrite* it
#
# Usage
#   $ ./purify.py filename [filenames...]
#
# Example
#   $ ./purify.py example.bib
#   $ ./purify.py example1.bib example2.bib
#
# LICENSE - MIT
#   Copyright 2019 Louie Lu
#
#   Permission is hereby granted, free of charge, to any person obtaining a copy
#   of this software and associated documentation files (the "Software"), to deal
#   in the Software without restriction, including without limitation the rights
#   to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
#   copies of the Software, and to permit persons to whom the Software is
#   furnished to do so, subject to the following conditions:
#
#   The above copyright notice and this permission notice shall be included in all
#   copies or substantial portions of the Software.
#
#   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
#   IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
#   FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
#   AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
#   LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
#   OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
#   SOFTWARE.
#

import sys
import bibtexparser

#
# 1) You can change the field you want to keep in each ENTRYTYPE
# 2) Any Field which is UPPERCASE will be remain (e.g. ID, ENTRYTYPE)
#
KEYS = {
    'common': {'author', 'year', 'booktitle', 'journal', 'title'},
    'inproceedings': {},
    'article': {'volume', 'number', 'pages'},
    'misc': {'url', 'urldate', 'howpublished'},
    'book': {'publisher'}
}


def purify(filename):
    with open(filename) as f:
        parser = bibtexparser.bparser.BibTexParser(common_strings=True)
        db = bibtexparser.load(f, parser=parser)

    for e in db.entries:
        typ = e['ENTRYTYPE']
        for k in list(e.keys()):
            if not k.isupper() and  k not in KEYS['common'] and k not in KEYS[typ]:
                del e[k]

    with open(filename, 'w') as f:
        f.write(bibtexparser.dumps(db))


def main(filenames):
    for filename in filenames:
        purify(filename)


if __name__ == '__main__':
    main(sys.argv[1:])

Make sure you have install bibtexparser first

$ python -m pip install bibtexparser --user