001、
[root@pc1 test]# cat a.fa >chr1 aatt cc >chr2 ttgg ccgg >chr3 aa [root@pc1 test]# cat test.py #!/usr/bin/python in_file = open("a.fa", "r") dict1 = dict() for i in in_file: i = i.strip() if i.startswith(">"): key = i dict1[key] = "" else: dict1[key] += i for i,j in dict1.items(): print(i.strip(">"), len(j)) in_file.close() [root@pc1 test]# python test.py ('chr1', 6) ('chr2', 8) ('chr3', 2)