def prot_similarity(blast_res):
    """
    Reads a blast tsv result and returns a dict with
    gene names as keys and query coverage as values.
    Assumes query name at column 2 and query coverage at column 10.
    """
    res = {}
    with open(blast_res) as f:
        for line in f:
            fields = line.strip().split('\t')
            res[fields[0]] = fields[9]
    return res