2019独角兽企业重金招聘Python工程师标准>>> 
bwa会输出mapping不上的reads例如：
A00268:187:H5HVYDSXX:2:1101:22824:1532 77 * 0 0 * * 0 0 TGGGCCTCGGCCAGCGGGTTGATCAGCACCTGCTCGTTGCGCAGGTCCATCTTGCGGTTGACCTTGGGCGGCCTTTTGGCGACGAAGACGCCGTTCTCGACATAGAGGTTGCCACGCTGCAGCTGCCGGCCATCGAACCAGCGGGCGTTC FF:FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF:FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF AS:i:0 XS:i:0
77 = 64+8+4+1(first segement+next segement in the template unmapped +segement unmapped+paired)
A00268:187:H5HVYDSXX:2:1101:22824:1532 141 * 0 0 * * 0 0 CCGCGACTTGCCCGCTGAAGCCTCCCGCCCTTGCGATTTCTGATCCCCCTCCTGCTGCTCGCCAGCGGCCTGGCCCAGGCACAGGCGACCGGGCAGCCCTACCAGGCCAGCGCCCCGCTGTCCTGGGAACTGAAGAACGCCCGCTGGTTC FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF AS:i:0 XS:i:0
所以会导求出来的wig文件有 * 这个作为scaffold，导致转化bw的时候出问题
