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Python Functional Python The Lambda Lambada Reduce

Posted by Emily Strobl
Emily Strobl
5,429 Points

dont know what to do

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.

im not getting what im suppose to do for this task

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(x):
    return x[0] * x[1]

1 Answer

Steven Parker
Steven Parker
230,274 Points
Steven Parker
Steven Parker
230,274 Points

Try breaking down the instructions into steps:

  • Create a variable named total.
  • Use map() to find the per-product totals for each item in prices, :point_left: using the function from task 1
  • then use reduce (and add) to find the total value. :point_left: the "map" expression will be the 2nd argument
Anupam Kumar
Anupam Kumar
3,795 Points
Anupam Kumar
Anupam Kumar
3,795 Points 
from functools import reduce
from operator import add

prices = [
    (6.99, 5),
    (2.94, 15),
    (156.99, 2),
    (99.99, 4),
    (1.82, 102)
]
def product_sales(dim):
    return dim[0]*dim[1]
total=reduce(add,list(map(product_sales,prices))) ```


what is wrong with the code ??
Steven Parker
Steven Parker
230,274 Points
Steven Parker
Steven Parker
230,274 Points

In future, create a fresh question for your issue.

But you're really close here, "map" already returns a list so you don't need the "list()" function.