打印张数最长的序列号列表（蟒蛇）

Question

我有号码的清单：

a=[2,3,4,5,1,3,2,4,5,6,2,6,7,5,2,7,5,6,2] 

我想不是包含2最长的序列，所以答案是：

[3,4,5,1,3] 

如何在python中做到这一点？ 感谢您帮助我，

Answer 1

您可以使用itertools.groupby()：

from itertools import groupby 

a = [2, 3, 4, 5, 1, 3, 2, 4, 5, 6, 2, 6, 7, 5, 2, 7, 5, 6, 2] 

# get the subsequences not containing 2 
subsequences = (list(it) 
       for contains_two, it in groupby(a, lambda x: x == 2) 
       if not contains_two) 

# find the longest one among them 
print(max(subsequences, key=len)) 

打印

[3, 4, 5, 1, 3]