I have a data-array like:
all = [[1,-1], [1,0], [1,1], [2,-1], [2,0], [2,1]] etc.
It has about 4000 pairs in it, but typically fewer on the order of a few hundred.
I need to find whether a two-valued array already exists in this large data-array, eg.
does [1,1] exist in the array?
So the function I need should act something like this:
isValid( all, [1,1] )
>>> True
isValid( all, [1,100] )
>>> False
I couldn’t get the numpy functions isin() or in1d() to do this for me. The one function I did find works, for lists, is:
all.index( [1,1] )
>> True
but when the arg is not in the all array, I have to try/catch a ValueError and the return False – acceptable for now, but not ideal.
>Solution :
You can use simple array lookup like this:
a = [[1,-1], [1,0], [1,1], [2,-1], [2,0], [2,1]]
[2,0] in a # True
[2,3] in a # False
or
a.index([2,0]) # result: 4
a.index([3,5]) # throw error, use try catch