# How do you divide each element in a list by an int?

### Question

I just want to divide each element in a list by an int.

``````myList = [10,20,30,40,50,60,70,80,90]
myInt = 10
newList = myList/myInt
``````

This is the error:

``````TypeError: unsupported operand type(s) for /: 'list' and 'int'
``````

I understand why I am receiving this error. But I am frustrated that I can't find a solution.

Also tried:

``````newList = [ a/b for a, b in (myList,myInt)]
``````

Error:

``````ValueError: too many values to unpack
``````

Expected Result:

``````newList = [1,2,3,4,5,6,7,8,9]
``````

EDIT:

The following code gives me my expected result:

``````newList = []
for x in myList:
newList.append(x/myInt)
``````

But is there an easier/faster way to do this?

1
122
10/22/2015 9:23:19 PM

The idiomatic way would be to use list comprehension:

``````myList = [10,20,30,40,50,60,70,80,90]
myInt = 10
newList = [x / myInt for x in myList]
``````

or, if you need to maintain the reference to the original list:

``````myList[:] = [x / myInt for x in myList]
``````
193
10/9/2014 10:02:02 PM

The way you tried first is actually directly possible with numpy:

``````import numpy
myArray = numpy.array([10,20,30,40,50,60,70,80,90])
myInt = 10
newArray = myArray/myInt
``````

If you do such operations with long lists and especially in any sort of scientific computing project, I would really advise using numpy.