相关疑难解决方法(0)

在Python中,in关键字的效率是多少,例如:

a = [1, 2, 3]
if 4 in a:
  ...

>>> x = numpy.array([[1, 2],
...                  [3, 4],
...                  [5, 6]])
>>> [1, 7] in x
True
>>> [1, 2] in x
True
>>> [1, 6] in x
True
>>> [2, 6] in x
True
>>> [3, 6] in x
True
>>> [2, 3] in x
False
>>> [2, 1] in x
False
>>> [1, 2, 3] in x
False
>>> [1, 3, 5] in x
False

我不知道__contains__ndarrays是如何工作的.我找的时候找不到相关的文档.它是如何工作的？它是否记录在任何地方？