Question

我正在为20个键建立一个相关矩阵，需要创建一个如下所示的数组，并且想知道如何使用循环来创建这样的数组。

 [[1],
 [0.3, 1],
 [0.3, 0.3, 1],
 [0.3, 0.3, 0.3, 1],
 [0.3, 0.3, 0.3, 0.3, 1],
 [0.3, 0.3, 0.3, 0.3, 0.3, 1],
 [0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 1],
 [0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 1],
 [0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 1],
 [0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 1],
 [0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 1],
 [0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 0.3, 1]]

Answer 1

您可以通过以下方式获取它：

[[0.3 for x in range(y)] + [1] for y in range(20)]

或等效地，通过：

[[0.3] * y + [1] for y in range(20)]

Answer 2

此处是代码的扩展版本。

#!/usr/bin/env python3


def generate_stepped_list(steps, last_number, repeated_number):
    """
    " @return a list (of `steps` length) of lists where each inner list is
    " one time longer than the previous one.
    " Lines are padded with repeated_number until the last position with
    " contains the last_number.
    " [[last_number],                                            -
    "  [repeated_number, last_number],                           ^
    "  [repeated_number, repeated_number, last_number]           | steps
    "   ...                                                      |
    "  [repeated_number, ... , repeated_number, last_number]]    -
    """
    stepped_list = []
    for i in range(steps):
        step = [repeated_number for x in range(i)]
        step.append(last_number)
        stepped_list.append(step)

    return stepped_list


if __name__ == "__main__":
    stepped_list_12 = generate_stepped_list(12, 1, 0.3)
    print(stepped_list_12)

这里使用列表推导（与@dcg相同，是对的）压缩了代码。

#!/usr/bin/env python3


def generate_stepped_list(steps, last_number, repeated_number):
    return [[repeated_number] * y + [last_number,] for y in range(steps)]

if __name__ == "__main__":                       
    stepped_list_12 = generate_stepped_list(12, 1, 0.3)        
    print(stepped_list_12)

Answer 3

所需的模式可以在嵌套循环的帮助下完成：-

pattern = []  # Creating list to store pattern by append method in list.
for x in range(12):        
     start = [1]
     for y in range(x):
         start = start + [0.3]
     pattern.append(start)
print(pattern)
for var in pattern:
    print(var)

如何创建这样的数组

3 个答案: