converting list of string to list of integer

Question

How do I convert a space separated integer input into a list of integers?

Example input:

list1 = list(input("Enter the unfriendly numbers: "))

Example conversion:

['1', '2', '3', '4', '5']  to  [1, 2, 3, 4, 5]

Solution 1

map() is your friend, it applies the function given as first argument to all items in the list.

map(int, yourlist) 

since it maps every iterable, you can even do:

map(int, input("Enter the unfriendly numbers: "))

which (in python3.x) returns a map object, which can be converted to a list. I assume you are on python3, since you used input, not raw_input.

Solution 2

One way is to use list comprehensions:

intlist = [int(x) for x in stringlist]

Solution 3

this works:

nums = [int(x) for x in intstringlist]

Solution 4

You can try:

x = [int(n) for n in x]

Solution 5

Say there is a list of strings named list_of_strings and output is list of integers named list_of_int. map function is a builtin python function which can be used for this operation.

'''Python 2.7'''
list_of_strings = ['11','12','13']
list_of_int = map(int,list_of_strings)
print list_of_int 

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Comments

[Rob I]

+1 but did you mean map(int,yourlist) ?

[Matt Fenwick]

This doesn't work. int is not a method on strings.

[Silviu]

Sorry I edited it... This is actually what I meant :)

[Matt Fenwick]

It's not wrong, but I generally wouldn't reuse x like that.

[Silviu]

Can you give me an example why?

[quodlibetor]

do you mean map(int, input().split()), or does py3k automatically convert space-separated input into a list?

[ch3ka]

no, I assumed that the digits are entered without whitespace, as the provided example suggests. In fact, I did not post this as a solution, I just wanted to point out that the second argument to map() does not have to be a list, any iterable works.

[georg]

+1, [int(x) for x in input().split()] to conform OP's specs.