Break a list into chunks of size N in Python

Difficulty Level : Medium
Last Updated : 24 Apr, 2020

Method 1: Using yield
The yield keyword enables a function to comeback where it left off when it is called again. This is the critical difference from a regular function. A regular function cannot comes back where it left off. The yield keyword helps a function to remember its state. The yield enables a function to suspend and resume while it turns in a value at the time of the suspension of the execution.

my_list = ['geeks', 'for', 'geeks', 'like',
           'geeky','nerdy', 'geek', 'love',
               'questions','words', 'life']
  
# Yield successive n-sized
# chunks from l.
def divide_chunks(l, n):
      
    # looping till length l
    for i in range(0, len(l), n): 
        yield l[i:i + n]
  
# How many elements each
# list should have
n = 5
  
x = list(divide_chunks(my_list, n))
print (x)

Output:

[['geeks', 'for', 'geeks', 'like', 'geeky'], 
 ['nerdy', 'geek', 'love', 'questions', 'words'], 
 ['life']]

Method 2: Using List comprehension
List comprehension is an elegant way to break a list in one line of code.

my_list = [1, 2, 3, 4, 5,
              6, 7, 8, 9]
  
# How many elements each
# list should have
n = 4 
  
# using list comprehension
final = [my_list[i * n:(i + 1) * n] for i in range((len(my_list) + n - 1) // n )] 
print (final)

Output:

[[1, 2, 3, 4], [5, 6, 7, 8], [9]]

Alternate Implementation :

l = [1, 2, 3, 4, 5, 6, 7, 8, 9] 
   
# How many elements each 
# list should have 
n = 4
   
# using list comprehension 
x = [l[i:i + n] for i in range(0, len(l), n)] 
print(x)

Output:

[[1, 2, 3, 4], [5, 6, 7, 8], [9]]

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Break a list into chunks of size N in Python