Python列表上的计算？

Question

我有这个清单：

[[54.1757, 57.7807], [61.5786, 64.1535], [67.9584, 83.0], [104.4185, 120.377]]

我想要做的是将此列表翻译成我有字符串的格式：

first_number:second_number-first_number

列表中的每一对。所以对于第一对，我会得到以下字符串：

"54.1757:3.605"

有关实施此方法的最佳方法的任何建议吗？

Answer 1

您可以使用list comprehension：

执行此操作

In [1]: arr = [[54.1757, 57.7807], [61.5786, 64.1535], [67.9584, 83.0], [104.4185, 120.377]]

In [2]: arr2 = [ "{}:{}".format(a, a-b) for a, b in arr ]

In [3]: arr2
Out[3]:
['54.1757:-3.605', '61.5786:-2.5749', '67.9584:-15.0416', '104.4185:-15.9585']

Answer 2

使用列表理解很容易做到。

>>> list = [[54.1757, 57.7807], [61.5786, 64.1535], [67.9584, 83.0], [104.4185, 120.377]]
>>>
>>> [ {x:y-x} for x, y in list ]
[{54.1757: 3.605000000000004}, {61.5786: 2.5748999999999924}, {67.9584: 15.041600000000003}, {104.4185: 15.9585}]
>>>