[英]Assigning to a new list just the last object of another list - Python
OK,在Python中,我有以下列表:
flowers = ["rose", "bougainvillea", "yucca", "marigold", "daylilly", "lilley of the valley"]
現在,我只想將列表花的最后一個對象分配給一個名為有毒的新列表。
我試過了:
poisonous=flowers[-1]
但是,此語句使有毒字符串而不是列表成為字符串。
>>> poisonous=[flowers[-1],] #take the last element and put it in a list
>>> poisonous
['lilley of the valley']
>>> poisonous=flowers[-1] #take the last element, which is a string
>>> poisonous
'lilley of the valley'
>>> poisonous=flowers[-1:] #take a slice of the original list. The slice is also a list.
>>> poisonous
['lilley of the valley']
試試這個
poisonous=flowers[-1:]
演示:
>>> flowers = ["rose", "bougainvillea", "yucca", "marigold", "daylilly", "lilley of the valley"]
>>>
>>> flowers[-1:]
['lilley of the valley']
您的問題是,您正在建立索引,這將返回一個對象。 而切片將返回一個列表。
您可以將要分配的對象包裝在方括號中,以使其成為列表分配。
poisonous = [flowers[-1]]
而且,可能更有用:
flowers = [
"rose",
"bougainvillea",
"poison oak",
"yucca",
"marigold",
"daylily",
"lily of the valley",
]
snakes = [
"king",
"rattler",
]
poisonous = []
poisonous.append(flowers[-1])
poisonous.append(snakes[-1])
print poisonous
--output:--
['lily of the valley', 'rattler']
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