Python - 列表理解如何一次插入 2 个元素？

Question

我pluralize在 python 中有一个函数可以打印单词的复数形式

pluralize("wolf") = wolves

例如，在我的 input_list 中

input_list = ["wolf","dog","cat","cow","pig"]

我可以做这个简单的列表理解来填充复数形式

output_list = [pluralize(data) for data in input_list]

给予 ["wolves","dogs","cats.....]

不过我需要

["wolves","wolf","dogs","dog","cats","cat","cows","cow"....]

我怎样才能得到这个由理解生成的列表？

我的意思是像

output_list = [pluralize(data),data for data in input_list]

（显然不起作用）

Answer 1

您可以添加另一个循环：

[word for data in input_list for word in (pluralize(data), data)]

演示：

>>> plural_forms = {'wolf': 'wolves', 'dog': 'dogs', 'cat': 'cats', 'cow': 'cows', 'pig': 'pigs'}
>>> pluralize = plural_forms.get
>>> input_list = ["wolf","dog","cat","cow","pig"]
>>> [word for data in input_list for word in (pluralize(data), data)]
['wolves', 'wolf', 'dogs', 'dog', 'cats', 'cat', 'cows', 'cow', 'pigs', 'pig']

Answer 2

sum([[x, plural(x)] for x in data], [])

同样地：

>>> sum([[x, x.upper()] for x in "hello"], [])
['h', 'H', 'e', 'E', 'l', 'L', 'l', 'L', 'o', 'O']