How to convert a string to a list?

Question

If I have a string:

a = 'hello'

How do I convert it into a list?

a = ['h', 'e', 'l', 'l', 'o']

score 4 · Accepted Answer · answered Oct 12 '15 at 13:41

4

A string is an iterable, and a list can be constructed from an iterable. So all you need is

a = list(a)
print(a)

Output:

['h', 'e', 'l', 'l', 'o']

answered Oct 12 '15 at 13:41

juanchopanza

Ow oke that works, Thanks! – V.ictor Oct 12 '15 at 13:43
Note: a list comprehension `[c for c in a]` should be [faster](http://stackoverflow.com/questions/22108488/are-list-comprehensions-and-functional-functions-faster-than-for-loops) – Pynchia Oct 12 '15 at 14:14
@Pynchia I have heard the opposite. If you have any evidence to back up that claim it would be good to see it! (I can't find it in the link you posted.) – juanchopanza Oct 12 '15 at 16:03
@juanchopanza I just timed it and it's kind of difficult to tell. `python3 -mtimeit -s'l=list(range(1000000))'` and `python3 -mtimeit -s'l=[el for el in range(1000000)]'`. Sometimes one or the other is faster. I must have misunderstood a discussion carried out here a few days ago [here](http://stackoverflow.com/questions/33001611/join-one-word-lines-in-a-file) – Pynchia Oct 12 '15 at 21:36
@Pynchia Same here, I never managed to spot a significant difference between the two (in python 2, haven't tried python 3.) – juanchopanza Oct 12 '15 at 21:37
@juanchopanza alright. Thank you for making me check. Good night – Pynchia Oct 12 '15 at 21:46

The6thSense · Answer 2 · 2015-10-12T14:01:48.007

0

Tried to do it differently

Code:

map(None,"sart")#for python 2.x
#list(map(None,"sart")) for python 3.x

Output:

['s', 'a', 'r', 't']

edited Oct 12 '15 at 14:01

answered Oct 12 '15 at 13:43

The6thSense

dowvoter could atleast say y so – The6thSense Oct 12 '15 at 13:50
Well, this is little interesting. How does it work? – Remi Guan Oct 12 '15 at 13:52
1

@KevinGuan map accepts a iterable and a function `i.e)map(function,iterable)` and a ll the iterable elements are passed to the function and output of map is list of function out .check this [out](http://stackoverflow.com/questions/10973766/understanding-the-map-function-python) – The6thSense Oct 12 '15 at 13:55
1

And note that this can only work on Python 2. On Python 3 you also need do something like `list(map(None,"sart"))`. – Remi Guan Oct 12 '15 at 13:55
@KevinGuan you are right :) pleasure is mine – The6thSense Oct 12 '15 at 13:56
@KevinGuan just for your curiosity you could also do `map(str,"sart") ` – The6thSense Oct 12 '15 at 13:56
1

Well, it's more interesting now. Maybe I really need see the document about `map()` again :) – Remi Guan Oct 12 '15 at 13:58
In python 3.5, `list(map(None, 'sart'))` gives `TypeError: 'NoneType' object is not callable` which is what I expected. I'm surprised this works in python 2. – saulspatz Oct 12 '15 at 14:38
This is really quite a pointless "solution". – juanchopanza Oct 12 '15 at 17:14
@juanchopanza I just pointed out it can be done this way also.I did not say it was efficient – The6thSense Oct 13 '15 at 05:26

2 Answers2