Question

我需要一些帮助将以下嵌套for循环转换为列表解析。

adj_edges = []
for a in edges:
    adj = []
    for b in edges:
        if b[0] < a[0] and b[1] >= a[0] and b[1] <= a[1]:
            adj.append(b)
    adj_edges.append((a[0], adj))

其中edge是像[[0,200]，[200,400]]这样的列表列表我之前使用过列表推导但我不知道为什么我遇到这个问题。

Answer 1

这里是：

adj_edges = [(a[0], [b for b in edges if b[0] < a[0] and b[1] >= a[0] and b[1] <= a[1]]) for a in edges]

这是一个互动会话，展示了两种替代方法：

>>> edges = [[0, 200], [200, 400]]
>>> adj_edges = []
>>> for a in edges:
...     adj = []
...     for b in edges:
...         if b[0] < a[0] and b[1] >= a[0] and b[1] <= a[1]:
...             adj.append(b)
...     adj_edges.append((a[0], adj))
... 
>>> adj_edges
[(0, []), (200, [[0, 200]])]
>>> [(a[0], [b for b in edges if b[0] < a[0] and b[1] >= a[0] and b[1] <= a[1]]) for a in edges]
[(0, []), (200, [[0, 200]])]

将for循环转换为list comprehension python

1 个答案: