import numpy as np
yourlist = [[0, 0, 0], [0, 1, 1], [1, 0, 2]]
a = np.array(yourlist)
print(a[:, (0)])
bc = np.bincount(a[:, (0)])
count = bc[bc == 1].size
count = np.count_nonzero(bc == 1)
First items in inner list efficiently as possible