单行for循环可构建具有多个值的字典列表

Question

我正在尝试将两个数组一起映射到字典列表。像这样：

a_list = [1, 2, 3]
b_list = ["a", "b", "c"]

d = [{"key1": a, "key2": b} for a in a_list for b in b_list]
>> [{"key1": 1, "key2": "a"}, {"key1": 2, "key2": "b"}, {"key1": 3, "key2": "c"}]

但是，这给出了：

[{"key1": 1, "key2": "a"}, {"key1": 1, "key2": "b"}, [...] {"key1": 3, "key2": "b"}, {"key1": 3, "key2": "c"}]

我尝试用for和and替换第二个,，以及将代码的一部分移到括号中来回移动。

Answer 1

使用def count_consecutive(arr, n): # pad a with False at both sides for edge cases when array starts or ends with n d = np.diff(np.concatenate(([False], arr == n, [False])).astype(int)) # subtract indices when value changes from False to True from indices where value changes from True to False return np.flatnonzero(d == -1) - np.flatnonzero(d == 1) count_consecutive(a, 5) # array([2, 1, 3])

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