# How to count unique tuples in the list?

I have a list of lets say 300 lenght. Each element consists tuple. Every tuple has 2 arrays. How can I count the unique tuples? I have 300 tuples here and I want to know how many of them are unique. I’m trying with converting list to the `set` and checking its `len` but I have such error:

``````---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-46-24c20fbb5e62> in <module>
----> 1 len(set(pair_list))

TypeError: unhashable type: 'list'
``````

My list looks like this:

``````[
(array([ 0.,  0.1,  0., -0.2, -0., -0.2, 0.,  0.1], [ 0.5,  0.2,  0.3, -0.1, -0.4, -0.2, 0.2,  0.1]), array([ 0.123,  0.14,  0.1, -0.22, -0.5, -0.2, 0.,  0.1])),
...,
(array(...), array(...))
]
``````

Edit: This is real sample of my data. Just one element of the list:

``````[array([[-0.63434589, -0.29900576,  1.58925953,  1.58925953, -1.25893308,
0.76126064, -0.87056499,  0.31736156, -3.86900902, -1.        ,
-0.23059131, -0.78751513,  0.510954  , -1.        , -0.30160512,
1.        ,  5.8423382 ,  0.02629687,  0.02696755,  1.65819659,
4.21574931, -1.        ,  0.        ,  1.        ,  0.        ,
0.        ,  0.        ,  0.        ,  0.        ,  0.        ],
[-1.        , -1.        , -1.        , -1.        , -1.        ,
-1.        , -1.        , -1.        , -1.        , -1.        ,
-1.        , -1.        , -1.        , -1.        , -1.        ,
-1.        , -1.        , -1.        , -1.        , -1.        ,
-1.        , -1.        , -1.        , -1.        , -1.        ,
-1.        , -1.        , -1.        , -1.        , -1.        ],
[-1.        , -1.        , -1.        , -1.        , -1.        ,
-1.        , -1.        , -1.        , -1.        , -1.        ,
-1.        , -1.        , -1.        , -1.        , -1.        ,
-1.        , -1.        , -1.        , -1.        , -1.        ,
-1.        , -1.        , -1.        , -1.        , -1.        ,
-1.        , -1.        , -1.        , -1.        , -1.        ]]),
array([ 0.     ,  0.14983,  0.     , -0.26847, -0.     , -0.26847,
-0.     ,  0.14983])],
``````

### >Solution :

You need to convert the `lists` to `tuples`, to be able to create a `set` out of them:

``````pairs_1 = [
[1,2], [3,4], [5,6], [7,8]
]

print(len(set(tuple(p) for p in pairs_1)))
``````

Out:

``````4
``````