python – How do you split a list into evenly sized chunks?

python – How do you split a list into evenly sized chunks?

Heres a generator that yields the chunks you want:

``````def chunks(lst, n):
Yield successive n-sized chunks from lst.
for i in range(0, len(lst), n):
yield lst[i:i + n]
``````

``````import pprint
pprint.pprint(list(chunks(range(10, 75), 10)))
[[10, 11, 12, 13, 14, 15, 16, 17, 18, 19],
[20, 21, 22, 23, 24, 25, 26, 27, 28, 29],
[30, 31, 32, 33, 34, 35, 36, 37, 38, 39],
[40, 41, 42, 43, 44, 45, 46, 47, 48, 49],
[50, 51, 52, 53, 54, 55, 56, 57, 58, 59],
[60, 61, 62, 63, 64, 65, 66, 67, 68, 69],
[70, 71, 72, 73, 74]]
``````

If youre using Python 2, you should use `xrange()` instead of `range()`:

``````def chunks(lst, n):
Yield successive n-sized chunks from lst.
for i in xrange(0, len(lst), n):
yield lst[i:i + n]
``````

Also you can simply use list comprehension instead of writing a function, though its a good idea to encapsulate operations like this in named functions so that your code is easier to understand. Python 3:

``````[lst[i:i + n] for i in range(0, len(lst), n)]
``````

Python 2 version:

``````[lst[i:i + n] for i in xrange(0, len(lst), n)]
``````

If you want something super simple:

``````def chunks(l, n):
n = max(1, n)
return (l[i:i+n] for i in range(0, len(l), n))
``````

Use `xrange()` instead of `range()` in the case of Python 2.x

python – How do you split a list into evenly sized chunks?

I know this is kind of old but nobody yet mentioned `numpy.array_split`:

``````import numpy as np

lst = range(50)
np.array_split(lst, 5)
# [array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]),
#  array([10, 11, 12, 13, 14, 15, 16, 17, 18, 19]),
#  array([20, 21, 22, 23, 24, 25, 26, 27, 28, 29]),
#  array([30, 31, 32, 33, 34, 35, 36, 37, 38, 39]),
#  array([40, 41, 42, 43, 44, 45, 46, 47, 48, 49])]
``````