sparse matrix from dictionaries
No. Any matrix in Scipy, sparse or not, must be instantiated with a size.
I just started to learn to program in Python and I am trying to construct a sparse matrix using Scipy package.  I found that there are different types of sparse matrices, but all of them require to store using three vectors like  row, col, data; or if you want to each new entry separately, like S(i,j) = s_ij you need to initiate the matrix with a given size.
My question is if there is a way to store the matrix entrywise without needing the initial size, like a dictionary.