How to take multiple values from a python list?

Question

I am creating a program that takes user input stores it in a list and then multiplies by either 5 or 1 alternating between each number. eg the first value is multiplied by 5 and the next 1 and so on. I want to remove all the values that i would multiply by 5 and add them to a separate list. How would this be done?

list1=[1,2,3,4]
list2=List1[???]

I have tried writing it like this: List2=List1[0,1] list2=List1[0][1] — Tom, Sep 27 '16 at 14:28

zipa · Accepted Answer · 2016-09-28T08:36:31.690

1

Here you go:

list1=[1,2,3,4]
list2 = [i*5 for i in list1[1::2]]

Two methods are used here slicing and list comprehension.

edited Sep 28 '16 at 08:36

answered Sep 27 '16 at 14:34

zipa

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Maybe explaining what you are doing to help OP understand, rather than just giving the answer? – MooingRawr Sep 27 '16 at 14:35
@MooingRawr You have a point. Hope OP finds these links useful. – zipa Sep 28 '16 at 08:38

score 0 · Answer 2 · edited May 23 '17 at 12:06

0

To get every other element, you could use a slice with a stride of two:

>>> list1 = [1,2,3,4]
>>> list2 = list1[::2]
>>> list2
[1, 3]

You can use a similar technique to get the remaining elements:

>>> list3 = list1[1::2]
>>> list3
[2, 4]

For further information, see Explain Python's slice notation

edited May 23 '17 at 12:06

Community

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answered Sep 27 '16 at 14:25

NPE

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This method doesn't remove the items from list1 that would be multiplied by 5 as OP mentioned. – Preston Martin Sep 27 '16 at 14:33

How to take multiple values from a python list?

2 Answers2