how to insert array in numpy using two variables

Question

if I have array: a=[1,2,3] b=[7,8,9] I want to get new array c=[1,7,2,8,3,9], which is alternating arrangement between a and b. How to use np.insert on that case?

Answer 1

# solution 1
import numpy as np
a=[1, 2, 3]
b=[7, 8, 9]
list(np.transpose((a,b)).flatten())
# output [1, 7, 2, 8, 3, 9]

# solution 2
import operator
a=[1, 2, 3]
b=[7, 8, 9]
reduce(operator.concat, map(lambda x, y : [x, y], a, b))
# output [1, 7, 2, 8, 3, 9]