Python Midpoint Rule (Rectangle Method)

Implementation of Midpoint Rule (Rectangle Method) (Integral Approximation) written in Python.

Enter beginning of interval: -2
Enter end of interval: 2
Enter number of iterations: 1000000
Integral is equal to: 5.333333333472218

# ? 2018 TheFlyingKeyboard and released under MIT License
# theflyingkeyboard.net


def function(x):
    return x * x


intervalBegin = float(input("Enter beginning of interval: "))
intervalEnd = float(input("Enter end of interval: "))
iterations = int(input("Enter number of iterations: "))

step = (intervalEnd - intervalBegin) / iterations
integral = 0

for i in range(iterations):
    integral += step * function(intervalBegin + (i - 1) * step)

print("Integral is equal to: ", integral)