python - "TypeError: ' int ' object is not iterable"当在函数内部移动 itertools 产品时

Question

我正在尝试在函数内移动 itertools.product 的用法。当我尝试执行此操作时，出现以下错误消息，但我不确定原因:

TypeError: 'int' object is not iterable

代码如下。在main函数中，可以看到函数外部使用的算法，然后可以看到函数内封装时使用的算法:

#!/usr/bin/env python

import itertools

def main():

    elements_specification = [[10, 20], [30, 40], [50, 60]]

    lists = [list(list_generated) for index, element_specification in enumerate(elements_specification) for list_generated in itertools.product(*elements_specification[:index + 1])]

    for list_configuration in lists:
        print(list_configuration)

    print("---")

    for list_configuration in list_element_combinations_variadic(
        [[10, 20], [30, 40], [50, 60]]
    ):
        print(list_configuration)

def list_element_combinations_variadic(
    elements_specification
    ):
    """
    This function accepts a specification of lists of elements for each place in
    lists in the form of a list, the elements of which are lists of possible
    elements and returns a list of lists corresponding to the combinations of
    elements of the specification with varying numbers of elements.

    For example, the list elements specification [[10, 20], [30, 40], [50, 60]]
    yields the following lists:

    [10]
    [20]
    [10, 30]
    [10, 40]
    [20, 30]
    [20, 40]
    [10, 30, 50]
    [10, 30, 60]
    [10, 40, 50]
    [10, 40, 60]
    [20, 30, 50]
    [20, 30, 60]
    [20, 40, 50]
    [20, 40, 60]
    """
    lists = [list(list_generated) for index, elements_specification in enumerate(elements_specification) for list_generated in itertools.product(*elements_specification[:index + 1])]
    return lists

if __name__ == "__main__":
    main()

Answer 1

基本上，您在 main 方法和另一个方法之间存在拼写错误。

在main中，您在for中正确地包含了element_specation

for index, element_specification in enumerate(elements_specification)

但是在另一种方法中，您在 for 中有 elements_specification

for index, elements_specification in enumerate(elements_specification) 

这恰好是该方法的参数名称，因此您要在列表理解中重新分配该参数

<小时/>

试试这个

lists = [list(list_generated) for index, element in enumerate(elements_specification) for list_generated in itertools.product(*elements_specification[:index + 1])]
return lists

或者，由于您甚至不需要 enumerate 中的 element，只需使用 range 即可。

lists = [list(list_generated) for index in range(len(elements_specification)) for list_generated in itertools.product(*elements_specification[:index + 1])]
return lists