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[英]Insert new column with values from a python list into an existing sql table
[英]Python 2: insert existing list inside of new explicit list definition
這可能是不可能的,但如果是的話,我寫的一些代碼會很方便:
ListOne = ['jumps', 'over', 'the']
ListTwo = ['The', 'quick', 'brown', 'fox', ListOne, 'lazy', 'dog!']
如果我這樣做,我最終會將ListOne作為ListTwo中的一個列表。
但相反,我想將ListOne擴展為ListTwo,但我不想做類似的事情:
ListOne = ['jumps', 'over', 'the']
ListTwo = ['The', 'quick', 'brown', 'fox']
ListTwo.extend(ListOne)
ListTwo.extend(['lazy', 'dog!']
這將有效,但它不像上面的代碼那樣可讀。
這可能嗎?
你可以使用+
運算符來連接列表:
ListOne = ['jumps', 'over', 'the']
ListTwo = ['The', 'quick', 'brown', 'fox'] + ListOne + ['lazy', 'dog!']
ListTwo
將是:
['The', 'quick', 'brown', 'fox', 'jumps', 'over', 'the', 'lazy', 'dog!']
另一種方法是使用切片賦值:
>>> ListOne = ['jumps', 'over', 'the']
>>> ListTwo = ['The', 'quick', 'brown', 'fox', 'lazy', 'dog!']
>>> ListTwo[4:4] = ListOne
>>> ListTwo
['The', 'quick', 'brown', 'fox', 'jumps', 'over', 'the', 'lazy', 'dog!']
>>> ListOne = ['jumps', 'over', 'the']
>>> from itertools import chain
>>> [x for x in chain(['The', 'quick', 'brown', 'fox'], ListOne, ['lazy', 'dog!'])]
['The', 'quick', 'brown', 'fox', 'jumps', 'over', 'the', 'lazy', 'dog!']
為什么不連接?
>>> ListTwo = ['The', 'quick', 'brown', 'fox']
>>> ListOne = ['jumps', 'over', 'the']
>>> ListTwo + ListOne
['The', 'quick', 'brown', 'fox', 'jumps', 'over', 'the']
>>> ListTwo + ListOne + ['lazy', 'dog!']
['The', 'quick', 'brown', 'fox', 'jumps', 'over', 'the', 'lazy', 'dog!']
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