定期分割列表列表,然后合并

时间:2018-11-13 16:06:44

标签: python

如何在每个第x个索引中“列”一个列表列表?

我正在考虑通过开始列表,然后创建两个新列表,合并它们,然后添加未被x整除的其余部分来做到这一点。

例如间隔2:

start = [
    [1, 'one'],
    [2, 'two'],
    [3, 'three'],
    [4, 'four'],
    [5, 'five'],
    [6, 'six'],
    [7, 'seven'],
    [8, 'eight'],
    [9, 'nine'],
]
expected = [
    [1, 'one', 3, 'three'],
    [2, 'two', 4, 'four'],
    # page break
    [5, 'five', 7, 'seven'],
    [6, 'six', 8, 'eight'],
    # page break
    [9, 'nine'],
]

只是想知道是否有一种快速的方法?

2 个答案:

答案 0 :(得分:0)

您是否正在寻找类似的东西?列平方矩阵?

start = [
    [1, 'one'],
    [2, 'two'],
    [3, 'three'],
    [4, 'four'],
    [5, 'five'],
    [6, 'six'],
    [7, 'seven'],
    [8, 'eight'],
    [9, 'nine'],
]
expected = [
    [1, 'one', 3, 'three'],
    [2, 'two', 4, 'four'],
    # page break
    [5, 'five', 7, 'seven'],
    [6, 'six', 8, 'eight'],
    # page break
    [9, 'nine'],
]
a = 2
r = a*a
ans = []
for i in range(0, len(start), r):
    l_tmp = start[i:i+r]
    if l_tmp[::a]:
        ans.append([item for sublist in l_tmp[::a] for item in sublist])
    if l_tmp[1::a]:
        ans.append([item for sublist in l_tmp[1::a] for item in sublist])
    # You can easily add page break here
print(ans)

答案 1 :(得分:0)

我同意有关这是一种奇怪的“聚集”方式的评论。但是,这是一个执行您所描述的功能的函数:

def columnize(A, interval=2):
    ans = []
    for i in range(0,len(A), interval*2):
        for j in range(min(interval, len(A)-i)):
            ans.append(A[i+j] + (A[i+j+interval] if i+j+interval < len(A) else []))
    return ans