x = [0,99, 'a', 1, 2, 'b',5, 3, 0,'a' ,1, 8, 5,'b',5,9,5] b=[] c=[] d=[] for i in range(len(x)): if 'a'==x[i]: b.append(i) elif 'b'==x[i]: c.append(i) print(b) print(c) if len(b)==len(c): for i in range(len(b)): d.append(x[b[i]:c[i]]) print(d)