How can we convert lists to integers?

Question

Hi, I'm in trouble.😂😂

I'd like to create a function ( having a list as argument) that converts a list (that contains only numbers) in integers for example [1,2,1,1] will become 1211.

I created a for-loop that stops when the length of the list is reached.
Then I put a variable that takes all the values of the list elements.

The problem is that I want all the elements and when I return the variable, it only returns the last element.

Quick overview of my code :

def convert_list(list) :
for i in range (len(list)) :
e = list[i]
return e

"Please I need somebody help! "🎵

Answer 1

Linou Saoudi let's review the code, assume we have a list like this:

[1,2,3,4]

First, prepare a value to return <rv>, and set its value to zero. Next we will iterate the list, and use each list elements' value (that is stored in variable <n>), on each iteration, the <n> value changes into:
1, 2, 3, 4

(1) rv = 0 * 10 + 1 => 1
(2) rv = 1 * 10 + 2 => 12
(3) rv = 12 * 10 + 3 => 123
(4) rv = 123 * 10 + 4 => 1234

There, now we have converted the list into a number, integer to be precise.

Hope it helps clear the doubt : )

Answer 2

A method with list operations, in case you need it.

lst = [1,2,1,1]
lstnum = int(''.join([str(x) for x in lst]))
print(lstnum)

Answer 3

def convert_list(l):
rv = 0
for n in l:
rv = rv * 10 + n
return rv

Hth, cmiiw

Answer 4

Linou Saoudi It's very easy to convert what I gave you to a function which returns an int. It would have been great if you could work on that yourself.

def convert_list(lst):
return int(''.join([str(x) for x in lst]))

Answer 5

You're welcome Linou, keep moving on 👍

Answer 6

Thank you very much. Can you just explain the lines you wrote please? Cause I didn't understand everything 😅

Answer 7

Ipang Thank you so much, I got it! :)

Answer 8

Thanks but I want to use a return not print 😅