@transform(mergeBams, suffix('.bam'), 
            ['.bam.flagstat', '.bam.countRunBam.Success'])
def countMergedBam(inputs, outputs):
    """
    Run samtools flagstat on the merged bam file.
    """
    bam, _success = inputs
    output, flag_file = outputs
    print bam % "Running samtools flagstat on %s"
    runStageCheck('flagstat', flag_file, bam, output)
dataset/ETHPy150Open vlsci/variant_calling_pipeline/pipeline.py/countMergedBam/swapped operands of `%`