如何删除列表中的多余解析字符？

Question

我有以下列表列表：

animals = [('dog', 'cat'), ('mouse', 'bird')]

我想将其简化为：

animals = ['dog', 'cat', 'mouse', 'bird']

有没有比做这样的事情更简单的方法来获得上面的结果：

animals = [('dog', 'cat'), ('mouse', 'bird')]

final = []

for a in animals:

    final.append(a[0])

    final.append(a[1])

print final

Answer 1

您可以使用itertools.chain.from_iterable：>>> from itertools import chain>>> list(chain.from_iterable(animals))['dog', 'cat', 'mouse', 'bird']或嵌套的list comprehension：>>> [anim for item in animals for anim in item]['dog', 'cat', 'mouse', 'bird']对于小型列表，请使用列表理解版本，否则请使用itertools.chain.from_iterable。>>> animals = [('dog', 'cat'), ('mouse', 'bird')]>>> %timeit list(chain.from_iterable(animals))100000 loops, best of 3: 2.31 us per loop>>> %timeit [anim for item in animals for anim in item]1000000 loops, best of 3: 1.13 us per loop>>> animals = [('dog', 'cat'), ('mouse', 'bird')]*100>>> %timeit list(chain.from_iterable(animals))10000 loops, best of 3: 31.5 us per loop>>> %timeit [anim for item in animals for anim in item]10000 loops, best of 3: 73.7 us per loop>>> animals = [('dog', 'cat'), ('mouse', 'bird')]*1000>>> %timeit list(chain.from_iterable(animals))1000 loops, best of 3: 296 us per loop>>> %timeit [anim for item in animals for anim in item]1000 loops, best of 3: 733 us per loop