How do check if an item exists in a multimensional numpy array?

Question

I have a array of numpy arrays

[array([5, 5, 5]), array([6, 6, 6])]

However if I try to check if an object exists in that array

[5, 5, 5] in x

I get this error

ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

Is there any way to fix this? Or am I doing something wrong?

First let's be clear, is x a list or ndarray? If ndarray how did you create it? You get the ambiguity error because in is using an equality test, and an_array==something produces a boolean array, many true/false values. alist==another_list produces a simple True/False. That's not the case with arrays. So in general in is a poor test when working with arrays. — hpaulj
– hpaulj, Commented Feb 1, 2020 at 19:46

Ethan · Accepted Answer · 2020-02-01 18:42:47Z

2

You are check to see if a list exists in an array of arrays. Convert your list to an array and it should work.

>>> x=np.array([np.array([5, 5, 5]), np.array([6, 6, 6])])
>>> np.array([5, 5, 5]) in x
True

answered Feb 1, 2020 at 18:42

Ethan

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