def is_read_on_correct_strand(strand, read):
    """Check if read is on expected strand."""
    if strand == '+' and (read.is_read1 and read.is_reverse or read.
        is_read2 and not read.is_reverse):
        return True
    elif strand == '-' and (read.is_read1 and not read.is_reverse or read.
        is_read2 and read.is_reverse):
        return True
    return False
