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Python Functional Python The Lambda Lambada Reduce

Any guidance is appreciated.


Finally, we're ready to find our totals. Create a variable named total. Use map() to find the per-product totals for each item in prices, then use reduce (and add) to find the total value.

My solution is attached.

from operator import add
from functools import reduce

prices = [
    (6.99, 5),
    (2.94, 15),
    (156.99, 2),
    (99.99, 4),
    (1.82, 102)

def product_sales(attribute):
    return attribute[0] * attribute[1]

total = list(map(product_sales, prices))
total = reduce(add, total)

Strange, your answer seems fine. I tested it, and it returned the correct answer. Unless I didn't understand the problem, it seems fine. Craig Dennis

No problem! :-)

1 Answer

Craig Dennis
Craig Dennis
Treehouse Teacher

Well...our test is currently being a little overly pedantic.

Try to collapse that last bit into one single line.

total = reduce(add, map(product_sales, prices))

I'll see if I can't clean that up a bit better. Your code is fine, the only thing that you don't really need is the coercion to a list. Reduce takes an iterable. So it only needs to iterate once through that way.