array multiplication with integer

Question

I have a 2D array "pop" in python. I want to multiply each element of column one with an integer. I used the following code

temp[i] = b*pop[i,0]+a*pop[i,1] 

But it is returning error "list indices must be integers or slices, not tuple"

Answer 1

import random
from random import sample
rows=20
a,b = 0.5,1 
pop=list(zip(sample(range(1, 100000), rows),sample(range(1, 100000), rows)))
profit = sample(range(1, 100000), rows)
#print(pop,profit)
mycombined=list(zip(pop,profit))
combined_array = np.asarray(mycombined)

print(combined_array)

m = len (combined_array) 
it = 1500 
#alpha = 0.01 

J=0
for i in range(1,m,1): 
     bpop=combined_array[i][0][0]
     apop=combined_array[i][0][1]
     aprofit=combined_array[i][1]
     temp=(bpop+apop-aprofit)**2
     J=J+temp

Now you have a list of lists and can use list comprehensions to change the values

1. pop contains a two variable tuple
2. profit is a list of random numbers
3. the result is a list of lists or tuples