Question

我想在列表列表中搜索和替换值。我拼凑了答案：

Flatten a nested list
Search for and replace a value
Regroup the flat list into a list of lists

我目前的代码有效，但我觉得它需要更复杂。有更优雅的方式吗？

# Create test data- a list of lists which each contain 2 items
numbers = list(range(10))
list_of_lists = [numbers[i:i+2] for i in range(0, len(numbers), 2)]

# Flatten the list of lists
flat_list = [item for sublist in list_of_lists for item in sublist]
# Search for and replace values
modified_list = [-1 if e > 5 else e for e in flat_list]
# Regroup into a list of lists
regrouped_list_of_lists = [modified_list[i:i+2] for i in range(0, len(modified_list), 2)]

Answer 1

您已经在使用列表推导，只需将它们组合起来：

replaced_list_of_lists = [
            [-1 if e > 5 else e for e in inner_list]
                for inner_list in list_of_lists
        ]

Answer 2

在嵌套列表解析中的子列表中进行替换，而不必展平和重新组合：

numbers = list(range(10))
list_of_lists = [numbers[i:i+2] for i in range(0, len(numbers), 2)]
# here
list_of_lists = [[-1 if e > 5 else e for e in sublist] for sublist in list_of_lists]

搜索和替换嵌套列表中的值的方法

2 个答案: