python小技巧

1 列表推导

>>> ref = [i for i in range(1,5)]
>>> ref
[1, 2, 3, 4]
>>> ref = ["chr"+str(chrom) for chrom in ref] #列表长度不变
>>> ref
['chr1', 'chr2', 'chr3', 'chr4']
>>> ref = [chrom+"-"+type for chrom in ref for type in ["gc%", "lengtn"]] #列表长度倍增
>>> ref
['chr1-gc%', 'chr1-lengtn', 'chr2-gc%', 'chr2-lengtn', 'chr3-gc%', 'chr3-lengtn', 'chr4-gc%', 'chr4-lengtn']