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Python Functional Python The Lambda Lambada Reduce

Posted by csr13
csr13
33,293 Points

Any guidance is appreciated.

CHALLENGE :

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.

prices.py 
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)
Alexander Davison
Alexander Davison
65,469 Points

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

Alexander Davison
Alexander Davison
65,469 Points

No problem! :-)

1 Answer

Craig Dennis
STAFF
Craig Dennis
Treehouse Teacher
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.

csr13
csr13
33,293 Points

Thank you! Craig Dennis Alexander Davison