在 Python 中为给定次数的迭代创建列表列表答案

【问题标题】：creating a list of lists for a given number of iterations in Python在 Python 中为给定次数的迭代创建列表列表
【发布时间】：2021-04-15 15:08:45
【问题描述】：

我正在处理下面的代码，其中有一个日期列表 (date_index) 和另一个列表 (date_unique)，其中包含 (date_index) 中出现的每个唯一日期。我正在尝试获取代码以从 date_index 中的 date_unique 返回每次出现 i 的索引。

for i in date_unique:
        month_index = [i for i in range(len(date_index)) if date_index[i] == (date_unique[0])]
        print(month_index)

例如上面 date_unique 中项目 0 的代码返回输出：

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]
[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]

如果我将代码更改为 date_unique[1] 我会得到输出

[16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45]

也重复了 11 次（根据 date_unique. 我希望得到的输出是：

[0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15], [16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45],
continued for i in date_unique.

如果您需要输入来测试

month_index = ['032020', '032020', '032020', '032020', '032020', '032020', '032020', '032020', '032020', '032020', '032020', '032020', '032020', '032020', '032020', '032020', '042020', '042020', '042020', '042020', '042020', '042020', '042020', '042020', '042020', '042020', '042020', '042020', '042020', '042020', '042020', '042020', '042020', '042020', '042020', '042020', '042020', '042020', '042020', '042020', '042020', '042020', '042020', '042020', '042020', '042020', '052020', '052020', '052020', '052020', '052020', '052020', '052020', '052020', '052020', '052020', '052020', '052020', '052020', '052020', '052020', '052020', '052020', '052020', '052020', '052020', '052020', '052020', '052020', '052020', '052020', '052020', '052020', '052020', '052020', '052020', '052020', '062020', '062020', '062020', '062020', '062020', '062020', '062020', '062020', '062020', '062020', '062020', '062020', '062020', '062020', '062020', '062020', '062020', '062020', '062020', '062020', '062020', '062020', '062020', '062020', '062020', '062020', '062020', '062020', '062020', '062020', '072020', '072020', '072020', '072020', '072020', '072020', '072020', '072020', '072020', '072020', '072020', '072020', '072020', '072020', '072020', '072020', '072020', '072020', '072020', '072020', '072020', '072020', '072020', '072020', '072020', '072020', '072020', '072020', '072020', '072020', '072020', '082020', '082020', '082020', '082020', '082020', '082020', '082020', '082020', '082020', '082020', '082020', '082020', '082020', '082020', '082020', '082020', '082020', '082020', '082020', '082020', '082020', '082020', '082020', '082020', '082020', '082020', '082020', '082020', '082020', '082020', '082020', '092020', '092020', '092020', '092020', '092020', '092020', '092020', '092020', '092020', '092020', '092020', '092020', '092020', '092020', '092020', '092020', '092020', '092020', '092020', '092020', '092020', '092020', '092020', '092020', '092020', '092020', '092020', '092020', '092020', '092020', '102020', '102020', '102020', '102020', '102020', '102020', '102020', '102020', '102020', '102020', '102020', '102020', '102020', '102020', '102020', '102020', '102020', '102020', '102020', '102020', '102020', '102020', '102020', '102020', '102020', '102020', '102020', '102020', '102020', '102020', '102020', '112020', '112020', '112020', '112020', '112020', '112020', '112020', '112020', '112020', '112020', '112020', '112020', '112020', '112020', '112020', '112020', '112020', '112020', '112020', '112020', '112020', '112020', '112020', '112020', '112020', '112020', '112020', '112020', '112020', '112020', '122020', '122020', '122020', '122020', '122020', '122020', '122020', '122020', '122020', '122020', '122020', '122020', '122020', '122020', '122020', '122020', '122020', '122020', '122020', '122020', '122020', '122020', '122020', '122020', '122020', '122020', '122020', '122020', '122020', '122020', '122020', '012021', '012021', '012021', '012021', '012021', '012021', '012021', '012021', '012021', '012021']

date_unique = ['032020', '042020', '052020', '062020', '072020', '082020', '092020', '102020', '112020', '122020', '012021']

我希望我的问题很清楚！非常感谢

【问题讨论】：

标签： python-3.x list iteration

【解决方案1】：

您应该迭代 date_unique 并将生成的列表附加到主列表中。

all_indices = []
for j in date_unique:
        month_index = [i for i in range(len(date_index)) if date_index[i] == (date_unique[j])]
        all_indices.append(month_index)

稍微短一点的方法是

all_indices = []
for date in date_unique:
        all_indices.append([i for i in range(len(date_index)) if date_index[i] == date])

【讨论】：

谢谢迪帕克！已经解决了，感谢您的帮助！