如何确定二维列表是否包含值？

Question

我有一个如下列表

mylist = [('value1', 'value2', 'value3'), ('secval1', 'secval2', 'secval3')]

如何查看列表是否包含“value2”？

Answer 1

使用any()：

any('value2' in sublist for sublist in mylist)

Answer 2

您只需使用any检查所有子列表：

any('value2' in subl for subl in mylist)

Answer 3

'value2' in (item for sublist in mylist for item in sublist)

Answer 4

类似于any()，一种也支持短路的解决方案：

>>> from itertools import chain
>>> mylist = [('value1', 'value2', 'value3'), ('secval1', 'secval2', 'secval3')]
>>> 'value2' in chain(*mylist)
True

证明它像any()：

那样短路

>>> it=chain(*mylist)
>>> 'value2' in it
True
>>> list(it) #part of iterable still not traversed
['value3', 'secval1', 'secval2', 'secval3']