[ACCEPTED]-How do I slice a string every 3 indices?-slice
In short, you can't.
In longer, you'll need 2 to write your own function, possibly:
def split(str, num):
return [ str[start:start+num] for start in range(0, len(str), num) ]
For 1 example:
>>> split("xxxXXX", 3)
['xxx', 'XXX']
>>> split("xxxXXXxx", 3)
['xxx', 'XXX', 'xx']
one difference between splitting lists into 8 chunks of 3 and strings into chunks of 3 7 is that the re module works with strings 6 rather than lists.
If performance is important 5 (ie you are splitting thousands of strings), you 4 should test how the various answers compare 3 in your application
>>> import re
>>> re.findall('...','XXXxxxXXXxxxXXXxxxXXXxxxXXX')
['XXX', 'xxx', 'XXX', 'xxx', 'XXX', 'xxx', 'XXX', 'xxx', 'XXX']
>>> chunksize=3
>>> re.findall('.{%s}'%chunksize,'XXXxxxXXXxxxXXXxxxXXXxxxXXX')
['XXX', 'xxx', 'XXX', 'xxx', 'XXX', 'xxx', 'XXX', 'xxx', 'XXX']
This works because . means 2 "match any character" in regular expressions.
.{3} means 1 "match any 3 characters", and so on
As far as I know there is no built in method 2 that allows you to chunk an str every x 1 indices. However this should works:
str = "stringStringStringString"
def chunk_str(str, chunk_size):
return [str[i:i+chunk_size] for i in range(0, len(str), chunk_size)]
chunk_str(str,3)
produces:
['str', 'ing', 'Str', 'ing', 'Str', 'ing', 'Str', 'ing']
Copying an answer from How do you split a list into evenly sized chunks in Python? since Nov 2008:
Directly 5 from the Python documentation (recipes for 4 itertools):
from itertools import izip, chain, repeat
def grouper(n, iterable, padvalue=None):
"grouper(3, 'abcdefg', 'x') --> ('a','b','c'), ('d','e','f'), ('g','x','x')"
return izip(*[chain(iterable, repeat(padvalue, n-1))]*n)
An alternate take, as suggested 3 by J.F.Sebastian:
from itertools import izip_longest
def grouper(n, iterable, padvalue=None):
"grouper(3, 'abcdefg', 'x') --> ('a','b','c'), ('d','e','f'), ('g','x','x')"
return izip_longest(*[iter(iterable)]*n, fillvalue=padvalue)
I guess Guido's time machine 2 works—worked—will work—will have worked—was 1 working again.
More Related questions
We use cookies to improve the performance of the site. By staying on our site, you agree to the terms of use of cookies.