List unused entries in latex bibliographies by parsing the aux file generated by biber

unused_references.py

#!/usr/bin/python
#-*- coding: utf-8
import os
import glob
from pybtex.database.input import bibtex
from pyparsing import Word, alphanums, Literal

auxfile = glob.glob("*.aux")[0]
bibfiles = []
parser = bibtex.Parser()

# Parse aux file and read used bib entries.
bib = Word(alphanums)
bibdata = Literal('\\abx@aux@cite{') + bib.setResultsName('bib') + Literal('}')
with open(auxfile, 'r') as file:
    tokens = bibdata.searchString(file.read())
    used = [token.bib for token in tokens]
    print "Found ", len(used), " used entries in ", auxfile

for fname in os.listdir("./"):
    if fname.endswith(".bib"):
        # Get list of defined keys
        entries = parser.parse_file(fname).entries.items()
        available = [entry[0] for entry in entries]
        #
        print "Found ", len(available), " available entries in ", fname
        unused = [entry for entry in available if not entry in used]
        print "Unused entries of ", fname, ": ", unused