fixDuplicates.py

import sys
from pysam import VariantFile

vcf_in = VariantFile(sys.argv[1])

print(str(vcf_in.header).strip())

for rec in vcf_in:
    for key, value in rec.info.items():
        if vcf_in.header.info[key].number not in ("A", "R", "G", ".", "0"):
            if type(value) is tuple:
                rec.info[key] = value[0:vcf_in.header.info[key].number]

    print(str(rec).strip())

Answer on biostars question: https://www.biostars.org/p/315408