Change certain elements in a list to an int

Question

I have a list:

aList = ['asdf123', '100', '45', '34hello']

how can I change it so the '100' and '45' becomes int rather than str?

aList = ['asdf123', 100, 45, '34hello']

Welcome to Stack Overflow! Please show what you have so far. For more information, see [how to ask a good question](http://stackoverflow.com/help/how-to-ask). — OneCricketeer, Oct 11 '16 at 16:33

broinjc · Answer 1 · 2016-10-11T18:55:44.337

2

You could use a helper function,

def to_int(s):
    try:
        return int(s)
    except:
        return s

aList = [to_int(n) for n in aList]

edited Oct 11 '16 at 18:55

answered Oct 11 '16 at 16:40

broinjc

1

It's useless to call `int(s)` first time, because it can raise exception in `return` statement. – vishes_shell Oct 11 '16 at 16:42
At the moment this is the only answer that uses a meaningful and PEP-8 compliant name for the function. Well done. – Matthias Oct 11 '16 at 16:51
aw, shucks, thank you :) – broinjc Oct 11 '16 at 18:55

score 0 · Answer 2 · answered Oct 11 '16 at 16:40

0

Define a method which will convert an integer or return the original value;

def tryInt(value):
    try:
        return int(value)
    except:
        return value

Then use map and lambda;

map( lambda x: tryInt(x), aList )

answered Oct 11 '16 at 16:40

CAB

Or list comprehension, `[tryInt(n) for n in aList]` – broinjc Oct 11 '16 at 16:42

score 0 · Answer 3 · answered Oct 11 '16 at 16:41

0

The following should get your there.

def convert(x):
    try:
        return int(x)
    except ValueError:
        return x

aList = map(convert, aList)

answered Oct 11 '16 at 16:41

Tammo Heeren

3 Answers3