Script for emulating the Zotero BetterBibtex stable citation key feature

zot5exp2bbt.py

#!/usr/bin/env python

'''
    Script for emulating the BetterBibtex stable citation key feature.
    (see https://github.com/retorquere/zotero-better-bibtex)

    input.bib:  A BibLatex export from a Zotero 5 library that has "Extra" field 
    			entries for stable BibTex keys ("bibtex: <my_key>"). They end up in the 
                note field of the standard Zotero 5 export.
    output.bib: A BibTex file where the citation keys from the Extra/note field are
                the real citation keys.
'''

import sys,re

if len(sys.argv)!=3:
	print("{0} <input.bib> <output.bib>".format(sys.argv[0]))
	exit(1)

regex_start=re.compile('@.*{(.*),')

data=open(sys.argv[1])

# Phase 1: Determine old key to new key mapping
old_key=None
mapping={}
for line in data:
	if line.startswith('@'):
		old_key=re.findall(regex_start,line)[0]
	elif '{bibtex:' in line:
		try:
			new_key=re.findall(r'.*{bibtex: *(.*)}',line)[0]
			new_key=new_key.replace('\\','')
			new_key=new_key.replace('{','')
			new_key=new_key.replace('}','')
			mapping[old_key]=new_key
		except:
			print("Broken entry: "+old_key)
		finally:
			entry_started=False

# Phase 2: Create new file, based on mapping
data.seek(0)
output=open(sys.argv[2],'w')
for line in data:
	if line.startswith('@'):
		old_key=re.findall(regex_start,line)[0]
		if old_key in mapping:
			line=line.replace(old_key, mapping[old_key])
		else:
			print("Not converted: "+old_key)
	if "note = {bibtex:" not in line:
		output.write(line)

output.close()
data.close()

Thanks for this, works like a charm!