Multiplying all negative values in a list

Question

can someone help me write code in Python for this problem?

x = [10,-5,6,-7,2,4,-9,12,-55,33,44,77]

Write up some code to multiply only the negative values. Print the result of these multiplications. Include a loop of some kind as well as an if-statement to grab just the negative numbers.

This is what I have so far:

x = [10,-5,6,-7,2,4,-9,12,-55,33,44,77]

for num in x:
    if num < 0:
        print (num, end = "")

Does this answer your question? [How can I multiply all items in a list together with Python?](https://stackoverflow.com/questions/13840379/how-can-i-multiply-all-items-in-a-list-together-with-python) — chickity china chinese chicken, Jul 21 '21 at 06:23

score 0 · Answer 1 · answered Jul 21 '21 at 05:20

0

IIUC, here's one way via reduce

from functools import reduce
x = [10, -5, 6, -7, 2, 4, -9, 12, -55, 33, 44, 77, -1]

result = reduce(lambda x, y: x*y, (i for i in x if i < 0))

OUTPUT:

answered Jul 21 '21 at 05:20

Nk03

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score 0 · Answer 2 · answered Jul 21 '21 at 05:38

0

You almost got it. I think they want you to do a simple script:

x = [10,-5,6,-7,2,4,-9,12,-55,33,44,77]

result = 1
for num in x:
    if num < 0:
        result = result * num
        # or result *= num

print(result)

answered Jul 21 '21 at 05:38

Prayson W. Daniel

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score 0 · Answer 3 · answered Jul 21 '21 at 06:26

0

With basic arithmetic and closest to your original version:

total = 0 if len(x)==0 else 1

for i in x:
    if i < 0:
        total *= i

print(total, end = "")

borrowing from https://stackoverflow.com/a/13843424/1248974

answered Jul 21 '21 at 06:26

chickity china chinese chicken

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Multiplying all negative values in a list

3 Answers3