2.4.1.A.sagews

from sympy import *

print("\n--- User input -----------------------")
fourth = S(1)/4
twelfth = fourth/3

# quantity = symbol:
b = var("b")

print("\n--- a: -------------------------------")

Ii = twelfth * b**4 * Matrix([54, 3, 2, 1])
Iy_A = sum(Ii)

# Steiner:
Ai =  b**2 * Matrix([6, 3, 2, 1])
zi = fourth * b * Matrix([1, -3, 5, -7])

# Iy_2 = sum( zi*zi * Ai ):
zq = zi.multiply_elementwise(zi)

Iy_B = zq.multiply_elementwise(Ai)
Iy_B = sum(Iy_B)

Iy = Iy_A + Iy_B

pprint("IyA:")
pprint(Iy_A)
pprint("\nIyB:")
pprint(Iy_B)
pprint("\nIy:")
pprint(Iy)

pprint("\nIy/mm^4(b=2):")

pprint(Iy.subs(b,2))

--- User input ----------------------- --- a: ------------------------------- IyA: 4 5*b IyB: 4 33*b ----- 4 Iy: 4 53*b ----- 4 Iy/mm^4(b=2): 212