how to remove duplicated elements from a list without using set()?

Question

Let

a = np.array([1, 1, 1,1,1,1])
b = np.array([2,2,2])

be two numpy arrays. Then let

c = [a]+[b]+[b]

clearly, c has duplicated elements b. Now I wish to remove one array b from c so that c only contains one a and one b

For removing duplicated elements in a list I usually used set(). However, if, this time, I do

set(c)

I would receive error like

TypeError: unhashable type: 'numpy.ndarray'

In my understanding is that the numpy.ndarray is not hashable.

The list c above is just an example, in fact my c could be very long. So, is there any good way to remove duplicated elements from a list of numpy.array?

Thx!

---

edit: I would expect my return to be c = [a]+[b]

Answer 1

You can use this

c = a.tolist() + b.tolist() + b.tolist()

And then

c = set(c)

Answer 2

I think the question is the same as the one below.
Removing duplicates from a list of numPy arrays

import numpy as np

a = np.array([1, 1, 1,1,1,1])
b = np.array([2,2,2])

arraylist = [a, b, b]
L = {array.tostring(): array for array in arraylist}
c = [v for v in L.values()]
c

result c:

[array([1, 1, 1, 1, 1, 1]), array([2, 2, 2])]

Answer 3

You can try this in the minimum lines of code:

list1 = [7,7,3,3,8]
list2 = []
for k in list1:
    if k not in list2:
        list2.append(k)
print(list2)  # Output: [7, 3, 8]