我如何更改此代码，以便可以处理功能

Question

The function below takes 3 parameters (f, a, and b). Here f is a function and a and b are lower and upper bounds respectively, and f is the function to be summed over. #to calculate the sum of f from a to b

def sum(f, a, b):
 total = 0
 for i in range(a, b+1):
 total += f(i)
 return total

Question 1. Type in the above code and calculate the sum of integers from 1 to 10, and 1 to 100 and 1 to 1000

Answer 1

Similar idea, but use *= instead of +=

def product(f, a, b):
    total = 1
    for i in range(a, b+1):
        total *= f(i)
    return total

For example

def foo(x):
    return x

>>> product(foo, 1, 5)
120

Answer 2

Just as adding 0 does nothing, multiplying by 1 does nothing. Therefore, just use that as the start:

def product(f, a, b):
    total = 1
    for i in range(a, b+1):
        total *= f(i)
    return total

Answer 3

Or use a functional style and you will come to success:

def product(f, a, b):
    return reduce(lambda x, y: x*y, [f(n) for n in range(a, b+1)])

---

Run it going with function eg spam :

def spam(x):
    return x

print(product(spam, 1, 3))

>>>6

Edited:

W/o f param it will looks:

def product(a, b):
    return reduce(lambda x, y: x*y, [n for n in range(a, b+1)])
print(product(1, 5))