How to split a string into a list of characters?
PythonStringListPython Problem Overview
How do I split a string into a list of characters? str.split
does not work.
"foobar" → ['f', 'o', 'o', 'b', 'a', 'r']
Python Solutions
Solution 1 - Python
>>> list("foobar")
['f', 'o', 'o', 'b', 'a', 'r']
Use the list
constructor.
Solution 2 - Python
You take the string and pass it to list()
s = "mystring"
l = list(s)
print l
Solution 3 - Python
You can also do it in this very simple way without list():
>>> [c for c in "foobar"]
['f', 'o', 'o', 'b', 'a', 'r']
Solution 4 - Python
If you want to process your String one character at a time. you have various options.
uhello = u'Hello\u0020World'
>Using List comprehension:
print([x for x in uhello])
Output:
['H', 'e', 'l', 'l', 'o', ' ', 'W', 'o', 'r', 'l', 'd']
>Using map:
print(list(map(lambda c2: c2, uhello)))
Output:
['H', 'e', 'l', 'l', 'o', ' ', 'W', 'o', 'r', 'l', 'd']
>Calling Built in list function:
print(list(uhello))
Output:
['H', 'e', 'l', 'l', 'o', ' ', 'W', 'o', 'r', 'l', 'd']
>Using for loop:
for c in uhello:
print(c)
Output:
H
e
l
l
o
W
o
r
l
d
Solution 5 - Python
If you just need an array of chars:
arr = list(str)
If you want to split the str by a particular delimiter:
# str = "temp//temps" will will be ['temp', 'temps']
arr = str.split("//")
Solution 6 - Python
I explored another two ways to accomplish this task. It may be helpful for someone.
The first one is easy:
In [25]: a = []
In [26]: s = 'foobar'
In [27]: a += s
In [28]: a
Out[28]: ['f', 'o', 'o', 'b', 'a', 'r']
And the second one use map
and lambda
function. It may be appropriate for more complex tasks:
In [36]: s = 'foobar12'
In [37]: a = map(lambda c: c, s)
In [38]: a
Out[38]: ['f', 'o', 'o', 'b', 'a', 'r', '1', '2']
For example
# isdigit, isspace or another facilities such as regexp may be used
In [40]: a = map(lambda c: c if c.isalpha() else '', s)
In [41]: a
Out[41]: ['f', 'o', 'o', 'b', 'a', 'r', '', '']
See python docs for more methods
Solution 7 - Python
The task boils down to iterating over characters of the string and collecting them into a list. The most naïve solution would look like
result = []
for character in string:
result.append(character)
Of course, it can be shortened to just
result = [character for character in string]
but there still are shorter solutions that do the same thing.
list
constructor can be used to convert any iterable (iterators, lists, tuples, string etc.) to list.
>>> list('abc')
['a', 'b', 'c']
The big plus is that it works the same in both Python 2 and Python 3.
Also, starting from Python 3.5 (thanks to the awesome [PEP 448](https://www.python.org/dev/peps/pep-0448/ 'Additional Unpacking Generalizations')) it's now possible to build a list from any iterable by unpacking it to an empty list literal:
>>> [*'abc']
['a', 'b', 'c']
This is neater, and in some cases more efficient than calling list
constructor directly.
I'd advise against using map
-based approaches, because map
does not return a list in Python 3. See https://stackoverflow.com/q/13638898/2301450.
Solution 8 - Python
split()
inbuilt function will only separate the value on the basis of certain condition but in the single word, it cannot fulfill the condition. So, it can be solved with the help of list()
. It internally calls the Array and it will store the value on the basis of an array.
Suppose,
a = "bottle"
a.split() // will only return the word but not split the every single char.
a = "bottle"
list(a) // will separate ['b','o','t','t','l','e']
Solution 9 - Python
Unpack them:
word = "Paralelepipedo"
print([*word])
Solution 10 - Python
To split a string s
, the easiest way is to pass it to list()
. So,
s = 'abc'
s_l = list(s) # s_l is now ['a', 'b', 'c']
You can also use a list comprehension, which works but is not as concise as the above:
s_l = [c for c in s]
There are other ways, as well, but these should suffice.
Later, if you want to recombine them, a simple call to "".join(s_l)
will return your list to all its former glory as a string...
Solution 11 - Python
You can use extend
method in list operations as well.
>>> list1 = []
>>> list1.extend('somestring')
>>> list1
['s', 'o', 'm', 'e', 's', 't', 'r', 'i', 'n', 'g']
Solution 12 - Python
If you wish to read only access to the string you can use array notation directly.
Python 2.7.6 (default, Mar 22 2014, 22:59:38)
[GCC 4.8.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> t = 'my string'
>>> t[1]
'y'
Could be useful for testing without using regexp. Does the string contain an ending newline?
>>> t[-1] == '\n'
False
>>> t = 'my string\n'
>>> t[-1] == '\n'
True
Solution 13 - Python
from itertools import chain
string = 'your string'
chain(string)
similar to list(string)
but returns a generator that is lazily evaluated at point of use, so memory efficient.
Solution 14 - Python
Well, much as I like the list(s) version, here's another more verbose way I found (but it's cool so I thought I'd add it to the fray):
>>> text = "My hovercraft is full of eels"
>>> [text[i] for i in range(len(text))]
['M', 'y', ' ', 'h', 'o', 'v', 'e', 'r', 'c', 'r', 'a', 'f', 't', ' ', 'i', 's', ' ', 'f', 'u', 'l', 'l', ' ', 'o', 'f', ' ', 'e', 'e', 'l', 's']