如何将基于频率的列表中的元素分组为元组

Question

我正在尝试将相似的数字组合成一个形式的元组(数字,频率).

l1=[2,2,2,5,5,7]

如何将此列表转换为下面的列表

l1=[(2,3),(5,2),(7,1)]

Answer 1

你可以这样做Counter():

from collections import Counter

l1 = [2, 2, 2, 5, 5, 7]

l1 = Counter(l1).items()

"key"是列表元素,"value"是出现次数.

例如:

In [7]: from collections import Counter

In [8]: l1=[2,2,2,5,5,7]

In [9]: Counter(l1).keys()
Out[9]: [2, 5, 7]

In [10]: Counter(l1).values()
Out[10]: [3, 2, 1]

In [11]: zip(Counter(l1).keys(), Counter(l1).values())
Out[11]: [(2, 3), (5, 2), (7, 1)]

In [12]: Counter(l1).items()
Out[12]: [(2, 3), (5, 2), (7, 1)]