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Python Python Collections (2016, retired 2019) Tuples Packing

Posted by Mathew Yangang
Mathew Yangang
4,433 Points

returning product

Where does slices come into play in this task. I keep getting 'try again' messages

twoples.py 
def multiply(base, *args):
    num = base
    for value in args:
        num = value*
    return num

3 Answers

Philip Schultz
Philip Schultz
11,437 Points
Philip Schultz
Philip Schultz
11,437 Points

Hey, just accept *args as a parameter. then declare the base inside and make it equal to 1 at first. Like so.

def multiply(*args):
    base = 1
    for item in args:
        base *= item
    return base

I'm still trying to figure out how to use it with slices also.....

Philip Schultz
Philip Schultz
11,437 Points
Philip Schultz
Philip Schultz
11,437 Points

Hey Craig Dennis , This is driving me crazy. I can't seem to find anyone solving this using slices in past posts for this challenge. Is there a way to use slices to solve this problem that would be considered more efficient than the results above?

Craig Dennis
Craig Dennis
Treehouse Teacher
Craig Dennis
Craig Dennis
Treehouse Teacher

This is the version using the slice hint.

def multiply(*args):
    result = args[0]
    # Here's the slice...all except the first one
    for arg in args[1:]:
        result *= arg
    return result

That make sense?

Alexander Davison
Alexander Davison
65,469 Points

Ah I see :)

Philip Schultz
Philip Schultz
11,437 Points
Philip Schultz
Philip Schultz
11,437 Points

Ok, that is interesting. Thanks Craig

Alexander Davison
Alexander Davison
65,469 Points
Alexander Davison
Alexander Davison
65,469 Points

I'm not sure where slices come into play, but this challenge can be accomplished using an accumulating variable holding the current product, and every iteration as you loop through the numbers, you multiply the accumulating variable by it.

def multiply(*nums):
    acc = 1
    for num in nums:
        acc *= num
    return acc

Or, if you like using FP (Functional Programming), you can use the reduce method from functools

from functools import reduce

def multiply(*nums):
    return reduce(lambda x, y : x * y, nums)
Craig Dennis
Craig Dennis
Treehouse Teacher
Craig Dennis
Craig Dennis
Treehouse Teacher

Don't forget operator.mul!

reduce(operator.mul, nums)
Mathew Yangang
Mathew Yangang
4,433 Points
Mathew Yangang
Mathew Yangang
4,433 Points

Thanks Craig