coo_creation.py

x,y = [],[]

for element in connections_list:
    xi = element[0]
    yi = element[1]
    
    x.append(xi)
    x.append(yi) # make symmetric
    y.append(yi)
    y.append(xi) # make symmetric

# create 'one' entries for the coo matrix
vals = np.ones(len(x))

# numpy(scipy.sparse)
from scipy.sparse import coo_matrix
m = coo_matrix((vals,(x,y)))